WO2025201873A1

WO2025201873A1 - Methods, communications devices, and infrastructure equipment

Info

Publication number: WO2025201873A1
Application number: PCT/EP2025/056647
Authority: WO
Inventors: Shin Horng Wong
Original assignee: Sony Europe Bv; Sony Group Corp
Current assignee: Sony Europe Bv; Sony Group Corp
Priority date: 2024-03-26
Filing date: 2025-03-11
Publication date: 2025-10-02
Anticipated expiration: 2026-09-26

Abstract

A method of operating a communications device configured to transmit signals to and/or to receive signals from an infrastructure equipment of a wireless communications network is provided. The method comprises receiving, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, receiving, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, determining, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and determining, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Description

METHODS, COMMUNICATIONS DEVICES, AND INFRASTRUCTURE EQUIPMENT

BACKGROUND

Field of Disclosure

The present disclosure relates to communications devices, infrastructure equipment, and methods for the more efficient and effective transmission and/or reception of data in a wireless communications network.

The present application claims the Paris Convention priority from European patent application number EP24166551.2, filed on 26 March 2024, the contents of which are hereby incorporated by reference.

Description of Related Art

The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

Previous generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support a wider range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to continue to increase rapidly.

Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles / characteristics depending on the application(s) it is running. For example, different considerations may apply for efficiently supporting data exchange with a smartphone when it is running a video streaming application (high downlink data) as compared to when it is running an Internet browsing application (sporadic uplink and downlink data) or being used for voice communications by an emergency responder in an emergency scenario (data subject to stringent reliability and latency requirements).

In view of this there is expected to be a desire for current wireless communications networks, for example those which may be referred to as 5G or new radio (NR) systems / new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements.

SUMMARY OF THE DISCLOSURE

The present disclosure can help address or mitigate at least some of the issues discussed above.

Embodiments of the present technique can provide a method of operating a communications device configured to transmit signals to and/or to receive signals from an infrastructure equipment of a wireless communications network. The method comprises receiving, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, receiving, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, determining, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and determining, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Such embodiments of the present technique, which, in addition to methods of operating communications devices, relate to methods of operating infrastructure equipment, to communications devices and infrastructure equipment, to circuitry for communications devices and infrastructure equipment, to wireless communications systems, to computer programs, and to computer-readable storage mediums, can allow for the more efficient and effective use of radio resources in a wireless communications network.

Respective aspects and features of the present disclosure are defined in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the present technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

Figure 1 schematically represents some aspects of an LTE-type wireless telecommunication system which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 2 schematically represents some aspects of a new radio access technology (RAT) wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 3 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured to operate in accordance with certain embodiments of the present disclosure; Figure 4 schematically represents a first example of non-overlapping sub-bands for uplink and downlink transmissions;

Figure 5 schematically represents second and third examples of non-overlapping sub-bands for uplink and downlink transmissions;

Figure 6 schematically illustrates an example of intra-cell cross link interference;

Figure 7 illustrates an example of transmission power leakage;

Figure 8 illustrates an example of receiver power selectivity;

Figure 9 illustrates an example of inter sub-band interference;

Figure 10 provides examples of different types of TDD slot format configurations;

Figure 11 illustrates a sub-band full duplex (SBFD) symbol configuration;

Figure 12 shows a part schematic, part message flow diagram representation of an example wireless communications system comprising a communications device and an infrastructure equipment in accordance with embodiments of the present technique;

Figure 13 illustrates how a slot format indicator (SFI) can be used to deactivate an uplink sub-band for an SBFD-capable UE in accordance with embodiments of the present technique;

Figure 14 illustrates how the radio resource control (RRC) parameter TDD-UL-DL-ConfigDedicated can be used to deactivate downlink sub-bands for an SBFD-capable UE in accordance with embodiments of the present technique;

Figure 15 illustrates how an SBFD-capable UE can be configured to reactivate deactivated sub-bands in accordance with embodiments of the present technique; and

Figure 16 shows a flow diagram illustrating an example process of communications in a communications system in accordance with embodiments of the present technique.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Long Term Evolution Advanced Radio Access Technology (4G)

Figure 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network / system 6 operating generally in accordance with LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [1], It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

The network 6 includes a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (i.e. a cell) within which data can be communicated to and from communications devices 4. Although each base station 1 is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the base station may be carried out by disparate, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

Data is transmitted from base stations 1 to communications devices 4 within their respective coverage areas 3 via a radio downlink (DL). Data is transmitted from communications devices 4 to the base stations 1 via a radio uplink (UL). The core network 2 routes data to and from the communications devices 4 via the respective base stations 1 and provides functions such as authentication, mobility management, charging and so on. Communications devices may also be referred to as mobile stations, user equipment (UEs), user terminals, mobile radios, mobile terminals, terminal devices, wireless transmit and receive units (WTRUs), and so forth. Services provided by the core network 2 may include connectivity to the internet or to external telephony services. The core network 2 may further track the location of the communications devices 4 so that it can efficiently contact (i.e. page) the communications devices 4 for transmitting downlink data towards the communications devices 4.

Base stations, which are an example of network infrastructure equipment, may also be referred to as transceiver stations, nodeBs, e-nodeBs, eNB, g-nodeBs, gNB and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

New Radio Access Technology (5G)

Systems incorporating NR technology are expected to support different services (or types of services), which may be characterised by different requirements for latency, data rate and/or reliability. For example, Enhanced Mobile Broadband (eMBB) services are characterised by high capacity with a requirement to support up to 20 Gb/s. The requirements for Ultra Reliable and Low Latency Communications (URLLC) services are for one transmission of a 32 byte packet to be transmitted from the radio protocol layer 2/3 SDU ingress point to the radio protocol layer 2/3 SDU egress point of the radio interface within 1 ms with a reliability of 1 - 10'⁵ (99.999 %) or higher (99.9999%) [2],

Massive Machine Type Communications (mMTC) is another example of a service which may be supported by NR-based communications networks. In addition, systems may be expected to support further enhancements related to Industrial Internet of Things (IIoT) in order to support services with new requirements of high availability, high reliability, low latency, and in some cases, high-accuracy positioning.

An example configuration of a wireless communications network which uses some of the terminology proposed for and used in NR and 5G is shown in Figure 2. In Figure 2 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a cell of the wireless communications network as represented by a circle 12. As such, wireless communications devices 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 20 may be connected to other networks 25.

The elements of the wireless access network shown in Figure 2 may operate in a similar way to corresponding elements of an LTE network as described with regard to the example of Figure 1. It will be appreciated that operational aspects of the telecommunications network represented in Figure 2, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

The TRPs 10 of Figure 2 may in part have a corresponding functionality to a base station or eNode B of an LTE network. Similarly, the communications devices 14 may have a functionality corresponding to the UE devices 4 known for operation with an LTE network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

In terms of broad top-level functionality, the core network 20 connected to the new RAT telecommunications system represented in Figure 2 may be broadly considered to correspond with the core network 2 represented in Figure 1, and the respective central units 40 and their associated distributed units / TRPs 10 may be broadly considered to provide functionality corresponding to the base stations 1 of Figure 1. The term network infrastructure equipment / access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may lie with the controlling node / central unit and / or the distributed units / TRPs. A communications device 14 is represented in Figure 2 within the coverage area of the first communication cell 12. This communications device 14 may thus exchange signalling with the first central unit 40 in the first communication cell 12 via one of the distributed units / TRPs 10 associated with the first communication cell 12.

It will further be appreciated that Figure 2 represents merely one example of a proposed architecture for a new RAT based telecommunications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless telecommunications systems having different architectures.

Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment / access node and the communications device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE-type base station 1 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment may comprise a control unit / controlling node 40 and / or a TRP 10 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein. A more detailed diagram of some of the components of the network shown in Figure 2 is provided by Figure 3. In Figure 3, a TRP 10 as shown in Figure 2 comprises, as a simplified representation, a wireless transmitter 30, a wireless receiver 32 and a controller or controlling processor 34 which may operate to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. As shown in Figure 3, an example UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44 which is configured to control the transmitter 49 and the receiver 48 to transmit signals representing uplink data to the wireless communications network via the wireless access interface formed by the TRP 10 and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with the conventional operation.

The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G/NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment / TRP / base station as well as the UE / communications device will in general comprise various other elements associated with its operating functionality.

As shown in Figure 3, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides a communication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

The interface 46 between the DU 42 and the CU 40 is known as the F 1 interface which can be a physical or a logical interface. The Fl interface 46 between CU and DU may operate in accordance with specifications 3GPP TS 38.470 and 3GPP TS 38.473, and may be formed from a fibre optic or other wired or wireless high bandwidth connection. In one example the connection 16 from the TRP 10 to the DU 42 is via fibre optic. The connection between a TRP 10 and the core network 20 can be generally referred to as a backhaul, which comprises the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the Fl interface 46 from the DU 42 to the CU 40.

In order for a UE such as UE 4 or 14 to transmit uplink data to the network (e.g. on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH)) to, for example, base station 1 or TRP 10, the UE must first ensure it is synchronised with the network on the uplink. Since a particular eNB or gNB expects to be receiving communications from many UEs, it needs to ensure that it shares a common timing understanding with each of these UEs (i.e. they are synchronised in terms of the starting times of frames and Orthogonal Frequency Division Multiplexing (OFDM) symbols). This is so that the eNB is able to schedule communication with each of them in a manner that avoids collisions and to ensure orthogonality of the uplink signals, such that inter-subcarrier interference is avoided or mitigated. Although reference is made to 5G networks, the discussions in this specification apply equally to 6G networks (and beyond) where there is expected to be significantly higher throughput, lower latency and higher reliability utilizing sub-THz frequencies.

Full Duplex Time Division Duplex (FD-TDD)

NR/5G networks can operate using Time Division Duplex (TDD), where an entire frequency band or carrier is switched to either downlink or uplink transmissions for a time period and can be switched to the other of downlink or uplink transmissions at a later time period. Currently, TDD operates in Half Duplex mode (HD-TDD) where the gNB or UE can, at a given time, either transmit or receive packets, but not both at the same time. As wireless networks transition from NR to 5G-Advanced networks, a proposed new feature of such networks is to enhance duplexing operation for Time Division Duplex (TDD) by enabling Full Duplex operation in TDD (FD-TDD) [3], [4],

In FD-TDD, a gNB can transmit and receive data to and from the UEs at the same time on the same frequency band. In addition, a UE can operate either in HD-TDD or FD-TDD mode, depending on its capability. For example, when UEs are only capable of supporting HD-TDD, FD-TDD is achieved at the gNB by scheduling a DL transmission to a first UE and scheduling a UL transmission from a second UE within the same orthogonal frequency division multiplexing (OFDM) symbol (i.e., at the same time). Conversely, when UEs are capable of supporting FD-TDD, FD-TDD is achieved both at the gNB and the UE, where the gNB can simultaneously schedule this UE with DL and UL transmissions within the same OFDM symbol by scheduling the DL and UL transmissions at different frequencies (e.g., physical resource blocks (PRBs)) of the system bandwidth. A UE supporting FD-TDD requires more complex hardware than a UE that only supports HD-TDD. Development of current 5G networks is focused primarily on enabling FD-TDD at the gNB with UEs operating in HD-TDD mode.

Motivations for enhancing duplexing operation for TDD include an improvement in system capacity, reduced latency, and improved uplink coverage. For example, in current HD-TDD systems, OFDM symbols are allocated only for either a DL or UL direction in a semi-static manner. Hence, if one direction experiences less or no data, the spare resources cannot be used in the other direction, or are, at best, under-utilized. However, if resources can be used for DL data and UL data (as in FD-TDD) at the same time, the resource utilization in the system can be improved. Furthermore, in current HD-TDD systems, a UE can receive DL data, but cannot transmit UL data at the same time, which causes delays. If a gNB or UE is allowed to transmit and receive data at the same time (as with FD-TDD), the traffic latency will be improved. In addition, UEs are usually coverage limited in their UL transmissions when located close to the edge of a cell. While the UE coverage at the cell-edge can be improved if more time domain resources are assigned to UL transmissions (e.g. repetitions), for HD-TDD systems, if the UL direction is assigned more time resources, fewer time resources can be assigned to the DL direction, which can lead to system imbalance. In contrast, in FD-TDD, continuous UL resources can be assigned for repetition opportunities whilst allowing DL traffic to occur in those resources, thereby UL enhancing coverage without causing system imbalance.

Sub-band Full Duplex (SBFD)

In Sub-band Full Duplex (SBFD), the frequency resource of a TDD system bandwidth or Bandwidth Part (BWP) (i.e. at the UE/gNB) is divided into two or more non-overlapping sub-bands, where each sub-band can be DL or UL [5], Guard sub-bands may be used between DL and UL sub-bands to reduce inter subband interference. In the current 5G system, only one UL sub-band can be configured in an OFDM symbol. An example is shown in Figure 4, where simultaneous DL and UL transmissions occur in three different non-overlapping sub-bands 401 to 403, i.e., in different sets of frequency Resource Blocks (RB): Subband#! 401, Sub-band#2 402, Sub-band#3 403. The example of Figure 4 is referred to as {DUD}, because two sub-bands, Sub-band# 1 401 and Sub-band# 3 403, are used for DL transmissions whilst one sub-band, Sub-band#2 402, is used for UL transmissions. To reduce leakage from one sub-band 401 to 403 to another, a guard sub-band 410 may be configured between UL and DL sub-bands 401 to 403. Guard sub-bands 410 are configured between DL Sub-band# 3 403 and UL Sub-band#2 402 and between UL Sub-band#2 402 and DL Sub-band# 1 401.

Figure 5 shows two further examples with a DL and UL sub-band separated by a guard sub-band, where here, the UL sub-band can be configured to occupy the lower frequency portion of the BWP whilst the DL sub-band occupies higher frequency portion of the BWP {UD} or the UL sub-band occupies the higher frequency portion of the BWP whilst the DL sub-band occupies lower frequency portion of the BWP {DU}. Here, on the left-side of Figure 5, a UL sub-band# 1 501 is separated from a DL sub-band#2 503 by a guard sub-band 502 - this sub-band arrangement is referred to as {UD} . In this case, the DL sub-band#2 503 occupies a higher frequency portion of the system bandwidth than the UL sub-band# 1 501. On the right-side of Figure 5, a DL sub-band# 1 504 is separated from a UL sub-band#2 506 by a guard sub-band 505 - this sub-band arrangement is referred to as {DU}. In this case, the UL sub-band#2 506 occupies a higher frequency portion of the system bandwidth than the DL sub-band# 1 504.

While Figures 4 and 5 show the system bandwidth as being divided into either two or three sub-bands, those skilled in the art would appreciate that the concept of SBFD may (in further releases of the 3GPP specifications, for example) be extended such that any number of sub-bands could be used, if deemed beneficial. For example, the system bandwidth may be divided into four sub-bands, which may, using the example of Figure 4, include the two downlink sub-bands 401, 403, the uplink sub-band 402 and another uplink sub-band, though other sub-band arrangements are envisioned. Guard sub-bands may be used in substantially any sub-band arrangement.

Intra-Cell Cross Link Interference (CLI)

FD-TDD employing SBFD suffers from intra-cell cross link interference (CLI) at the gNB and at the UE. An example is shown in Figure 6, where a gNB 610 is capable of FD-TDD and is simultaneously receiving UL transmission 631 from UE1 621 and transmitting a DL transmission 642 to UE2 622. At the gNB 610, intra-cell CLI is caused by the DL transmission 642 at the gNB’s transmitter self-interfering 641 with its own receiver that is trying to decode UL signals 631. At UE2 622, intra-cell CLI 632 is caused by an aggressor UE, e.g. UE1 621, transmitting in the UL 631, whilst a victim UE, e.g. UE2 622, is receiving a DL signal 642.

The intra-cell CLI at the gNB due to self-interference can be significant, as the DL transmission can in some cases be over 100 dB more powerful than the UL reception. Accordingly, complex RF hardware and interference cancellation are required to isolate this self-interference. As noted above, guard bands may be inserted between two sub-bands of different link directions as shown in Figures 4 and 5 and described above. Furthermore, separate antenna panels may be used for transmissions and receptions at the gNB to provide spatial isolation between the DL & UL thereby reducing gNB self-interference.

Inter Sub-Band Interference

The use of SBFD is considered as a way of reducing self-interference at the gNB. However, SBFD may suffer from inter (and indeed intra) sub-band interferences, which are caused by transmission leakage and receiver’s selectivity. Although a transmission is typically scheduled within a specific frequency channel (or sub-band), i.e. a specific set of RBs, transmission power can leak out to other channels. This occurs because channel filters are not perfect, and as such the roll-off of the filter will cause power to leak into channels adjacent to the intended specific frequency channel. While the following discussion uses the term channel, the discussion equally applies to sub-bands, such as the sub-bands shown in Figures 4 and 5.

An example of transmission generating adjacent channel leakage is shown in Figure 7. Here, the wanted transmission (Tx) power is the transmission power in the selected frequency band (i.e. the assigned channel 710). Due to roll-off of the transmission filter and nonlinearities in components of the transmitter, some transmission power is leaked into adjacent channels (including an adjacent channel 720), as shown in Figure 7. The ratio of the power within the assigned frequency channel 710 to the power in the adjacent channel 720 is the Adjacent Channel Leakage Ratio (ACLR). The leakage power 750 will cause interference at a receiver that is receiving the signal in the adjacent channels 720.

Similarly, a receiver’s filter is also not perfect and will receive unwanted power from adjacent channels due to its own filter roll-off. An example of filter roll-off at a receiver is shown in Figure 8. Here, a receiver is configured to receive transmissions in an assigned channel 810. However, the imperfect nature of the receiver filter means that some transmission power 850 can be received in adjacent channels 820. Therefore, if a signal 830 is transmitted on an adjacent channel 820, the receiver will inadvertently receive the adjacent signal 830 in the adjacent channel 820, to an extent. The ratio of the received power in the assigned frequency channel 810 to the received power 850 in the adjacent channel 820 is the Adjacent Channel Selectivity (ACS).

The combination of the ACL from the transmitter and the ACS of a receiver will lead to adjacent channel interference (ACI), otherwise known as inter-sub-band interference, at the receiver. An example is shown in Figure 9, where an aggressor transmits a signal 910 in an adjacent channel at a lower frequency than the victim’s receiving 920 channel. The interference 950 caused by the aggressor’s transmission includes the ACL 951 of the aggressor’s transmitting filter and the ACS 952 of the victim’s receiving filter. In other words, the receiver will experience interference 950 in the ACI frequency range shown in Figure 9.

As such, due to adjacent channel interference (ACI), cross link interference (CLI) will still occur despite the use of different sub-bands 401 to 403 for DL and UL transmissions in a FD-TDD cell as shown in the example of Figure 4, or sub bands 501 and 503, and 504 and 506 in the examples of Figure 5.

Slot Format Configurations

In the legacy TDD system, an OFDM symbol can be configured as Downlink (DL), Uplink (UL) or Flexible (FL). DL OFDM symbols can be used by the gNB to transmit downlink transmissions to the UE whilst UL OFDM symbols can be used by the UE to transmit uplink transmissions to the gNB. FL OFDM symbols can be further configured into DL or UL OFDM symbols. There are four ways to configure the TDD slot format, where two of them are semi-static configurations and another two are dynamic configurations, i.e.:

• Semi-static configurations: o Cell specific configuration; and o UE dedicated configuration;

• Dynamic configurations: o Slot Format Indicator (SFI); and o DL or UL Grant. An example using showing all four ways of indicating TDD Slot Format configurations is shown in Figure 10. The cell specific configuration 1001 is signalled in the System Information Blocks (SIBs) using the Radio Resource Control (RRC) parameter TDD-UL-DL-ConfigCommon, where up to two TDD patterns can be configured (where, here, the second TDD pattern is optional). In each TDD pattern, the number of consecutive DL slots and DL OFDM symbols are configured from the start of the TDD pattern, and the number of consecutive UL slots and UL OFDM symbols are configured from the end of the TDD pattern. Any remaining OFDM symbols not configured as DL or UL are FL OFDM symbols.

For example, in Figure 10, two TDD patterns are configured; a first TDD pattern 1011 and a second TDD pattern 1012, where each pattern has a duration of five slots (where it should be noted that the two TDD patterns can have different durations). In the first TDD pattern 1011, which is shown in the example of Figure 10 to occupy Slot n to Slot w+4, N1 DL-siot = 2 consecutive slots are DL from the start of the pattern followed by AT DL-symboi = 7 DL OFDM symbols. From the end of the first TDD pattern 1011 , N1 uL-siot = 1 slot is UL followed by N1 uL-symboi = 6 UL OFDM symbols. The remaining OFDM symbols between the DL and UL OFDM symbols for the first TDD pattern 1011 are FL OFDM symbols occupying part of Slot n+2 and Slot n+3. For the second TDD pattern 1012, which occupies Slot n+5 to Slot n+9, the DL OFDM symbols are configured in the first N2oL-siot = 1 slot and followed by N2DL -Symbol 8 OFDM symbols form the start of the second TDD pattern 1012. The UL OFDM symbols are configured from N2uL-siot = 2 slots and followed by N2uL-symboi = 7 UL OFDM symbols from the end of the second TDD pattern 1012. Similarly to the first TDD pattern 1011, the OFDM symbols between the indicated DL and UL OFDM symbols for the second TDD pattern 1012 occupying part of Slot w+6 and slot w+7 are FL OFDM symbols.

The TDD Slot Format can be further configured using a UE dedicated configuration 1002 configured via the RRC parameter TDD-UL-DL-ConfigDedicated, where FL OFDM symbols configured from the cell specific TDD Slot Format configuration 1001 can be further configured into DL, UL or remain as FL OFDM symbols. Using the example in Figure 10, the first 6 FL OFDM symbols and the first 7 FL OFDM symbols of Slot w+3 and Slot w+7 are re-configured by the semi-static UE-dedicated configuration 1002 as DL and UL OFDM symbols respectively, as illustrated by the black dashed boxes shown in Figure 10 for the cell specific configuration 1001 and the UE dedicated configuration 1002.

The remaining FL OFDM symbols after the semi-static configurations have been applied can be dynamically indicated into DL or UL symbols, or can remain as FL OFDM symbols, and this can be dynamically configured 1003 using the Slot Format Indicator (SFI), which is transmitted in a PDCCH using a Group Common DCI with DCI Format 2_0 with the cyclic redundancy code (CRC) scrambled by an SFI-radio network temporary identifier (SFI-RNTI). The SFI indicates an index to an entry in the lookup table, which is Table 11.1.1-1 of [6], where each entry of the lookup table indicates a slot format, i.e., the locations of DL, UL and FL OFDM symbols within a slot. In the example in Figure 10, an SFI is transmitted to a group of UEs in Slot w+1 to configure the slot format of Slot w+2, where here the SFI indicates an index = 33, which effectively configures the 7 FL OFDM symbols in Slot n+2 after the UE dedicated configuration 1002, to 2 DL, 3 FL and 2 UL OFDM symbols, as illustrated by the black dashed box shown in Figure 10 for the SFI configuration 1003.

OFDM symbols that remain as FL OFDM symbols (e.g. after semi-static configurations 1001, 1002 and/or SFI dynamic indication 1003) can further be indicated dynamically 1004 as DL or UL OFDM symbols via a DL Grant or an UL Grant respectively. This is done by scheduling a PDSCH or PUSCH over FL OFDM symbols, thereby dynamically configuring them into DL and UL OFDM symbols respectively. In the example in Figure 10, a DL Grant carried by a PDCCH is transmitted in Slot n+2 to a UE scheduling a PDSCH starting from the fourth OFDM symbol to the twelfth OFDM symbol of Slot n+2, where the tenth, eleventh, and twelfth OFDM symbols of Slot n+2 are FL OFDM symbols. That is, the DL Grant by scheduling a PDSCH over FL OFDM symbols dynamically configures them into DL OFDM symbols. Similarly, an UL Grant in Slot n+5 schedules a PUSCH in the last 4 FL OFDM symbols of Slot n+6, thereby dynamically configuring these FL OFDM symbols into UL OFDM symbols. Again, this is indicated by the black dashed boxes shown in Figure 10 for the DL/UL grant configuration 1004.

Technical Issue with Indicating Subsequent Slot Format Configuration to SBFD UEs

In addition to DL, UL and FL OFDM symbols, SBFD OFDM symbol is introduced in Rel-19, where an SBFD OFDM symbol consists of one UL sub-band and either one or two DL sub-bands as shown in Figures 4 and 5. In Rel-19, SBFD OFDM symbols are semi-statically configured, where SBFD OFDM symbols can be configured on DL OFDM symbols and/or FL OFDM symbols that are cell-specifically configured. One of the objectives of Duplex Evolution is to increase UL capacity and so at least for Rel- 19, SBFD is only configured in DL and/or FL OFDM symbols, i.e., by configuring a UL sub-band in DL and/or FL OFDM symbols. That is, DL OFDM symbols and FL OFDM symbols configured cell specifically using the parameter TDD-UL-DL-ConfigCommon, can be further semi-statically configured into SBFD OFDM symbols using a new RRC configuration message. DL, UL and FL OFDM symbols configured using TDD-UL-DL-ConfigCommon are termed herein as original DL, UL and FL OFDM symbols respectively.

An example is shown in Figure 11, where a TDD Slot Format {DDDSU}, consisting of three DL slots, one slot with DL and FL OFDM symbols, and one UL slot is, cell specifically configured 1101 using the RRC parameter TDD-UL-DL-ConfigCommon. In this example, Slot w+1 and Slot n+2, which consist of original DL OFDM symbols, and Slot n+2>, which consists of original DL and original FL OFDM symbols, are configured (e.g., by another RRC configuration 1102 such as a UE-dedicated configuration) into SBFD OFDM symbols with a {DUD} sub-band arrangement - as shown by the black dashed boxes in Figure 11. In Rel-19, original UL OFDM symbols, i.e., UL OFDM symbols configured via TDD-UL- DL-ConfigCommon, are not used for configuration of SBFD OFDM symbols as described above.

In Rel-19, SBFD OFDM symbol configuration is not dynamically configured to reduce complexity in managing CLI among gNBs. Hence, an original DL or FL OFDM symbol that is configured as SBFD OFDM symbol such as in the example of Figure 11 cannot be dynamically configured back to non-SBFD OFDM symbols. The behaviour or SBFD-capable UEs when receiving an SFI needs to be specified. In addition to SFI, the behaviour of SBFD-capable UEs when receiving a UE dedicated Slot Format configuration via UL-DL-ConfigDedicated also needs to be specified. Embodiments of the present technique seek to provide solutions to address such requirements.

SBFD UE Behaviour for Legacy Slot Format Configurations

Figure 12 shows a part schematic, part message flow diagram representation of a wireless communications system comprising a communications device 1210 (e.g., a UE 14) and an infrastructure equipment 1220 (e.g., an AP such as a gNB / TRP 10) in accordance with at least some embodiments of the present technique. The communications device 1210 may be configured to transmit signals to and/or receive signals from the wireless communications network, for example, to and from the infrastructure equipment 1220. Specifically, the communications device 1210 may be configured to transmit data to and/or receive data from the wireless communications network (e.g., to/from the infrastructure equipment 1220) via a wireless radio interface provided by the wireless communications network (e.g., a Uu interface between the communications device 1210 and the Radio Access Network (RAN), which includes the infrastructure equipment 1220). The communications device 1210 and the infrastructure equipment 1220 each comprise a transceiver (or transceiver circuitry) 1211, 1221, and a controller (or controller circuitry) 1212, 1222. Each of the controllers 1212, 1222 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc. The controllers 1212, 1222 may also each be equipped with a memory unit (which is not shown in Figure 12).

As shown in the example of Figure 12, the controller 1212 of the communications device 1210 is configured to control the transceiver 1211 of the communications device 1210 to receive 1230, from the infrastructure equipment 1220, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device 1210 and the infrastructure equipment 1220, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to receive 1240, from the infrastructure equipment 1220, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non- SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to determine 1250, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to determine 1260, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Here, prior to the first slot format configuration there may be a cell specific configuration or the like as described above with respect to Figure 10, and may be configured via RRC signalling, for example using the parameter TDD-UL-DL-ConfigCommon to indicate the first pattern (of DL, UL, and FL symbols) for the non-SBFD symbols of the time-divided slots (i.e. before any later SFBD sub-band configuration for SFBD-capable UEs) for both SBFD-capable and non-SBFD-capable (i.e. legacy) UEs. The first slot format configuration may then consist of a new semi-static slot format configuration (e.g. a new RRC message, a new information element (IE) in an existing RRC message, or in a system information block (SIB)) to configure SBFD OFDM symbols for only SBFD capable UEs along with the first pattern - where this first pattern may have been indicated previously in a prior slot format configuration to both SFBD and non-SFBD UEs as described above. In other words, the first slot format configuration may be an SBFD configuration, wherein the SBFD configuration indicates the one or more SBFD symbols of the one or more time-divided slots, and wherein the SBFD configuration is received from the infrastructure equipment in RRC signalling. Here, the communications device 1210 in the example of Figure 12 is an SBFD capable UE, meaning that it is able to understand SBFD configurations and transmit signals and receive signals at the same time (i.e. in accordance with a full duplex operation) using configured SBFD UL and DL sub-bands.

Here, the second slot format configuration may be for example a UE dedicated configuration, which is configured for UEs (which may be SBFD or non-SBFD capable) via RRC signalling, for example using the parameter TDD-UL-DL-ConfigDedicated. Alternatively, the second slot format configuration may be a Slot Format Indicator (SFI) indicated dynamically to one or more UEs using a GC-DCI or the like. Here, the first and second pattern each refer to a different pattern of uplink, downlink and flexible symbols, where it may be the flexible symbols in the subset that can be reconfigured with the second slot format configuration, or any types of symbols may be reconfigured.

Essentially then, embodiments of the present technique, as exemplified by the example wireless communications system of Figure 12 for example, propose that SBFD capable UEs interpret subsequent slot format configurations differently for SBFD OFDM symbols and non-SBFD OFDM symbols. In some arrangements of embodiments of the present technique, the SBFD capable UE interprets subsequent slot format configuration for SBFD OFDM symbols as an activation or deactivation of a specific sub-band for SBFD OFDM symbols. In other words, the second modification may comprise one or more sub-bands within one or more of the SBFD symbols of the subset being activated or deactivated. That is, the link direction of an OFDM symbol indicated by the subsequent slot format configuration indicates that the sub-band with the same link direction is active whilst the sub-band with the opposite link direction is deactivated.

An activated DL sub-band and activated UL sub-band are used for DL reception and UL transmission respectively. In other words, the communications device may be configured, after the one or more subbands within one or more of the SBFD symbols of the subset are activated, to transmit, in at least one of the activated sub-bands if the at least one activated sub-band is an uplink sub-band, uplink signals to the infrastructure equipment, and/or to receive, in at least one of the activated sub-bands if the at least one activated sub-band is a downlink sub-band, downlink signals from the infrastructure equipment.

However, a deactivated DL sub-band and deactivated UL sub-band are not used for DL reception and UL transmission respectively. In other words, the communications device may be configured, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, to transmit uplink signals to and/or to receive downlink signals from the infrastructure equipment only in radio resources of the one or more time-divided slots that are outside of the one or more deactivated sub-bands, and not within the deactivated sub-bands. This recognises that for an OFDM symbol, notably an original FL OFDM symbol, which is indicated by the said subsequent slot format configuration as DL or UL, legacy UEs may be receiving or transmitting respectively assuming all the frequency resources in that OFDM symbol are used for that purpose. This may lead to high CLI especially if a legacy UE is receiving in frequency resources that overlaps with those symbols of an UL sub-band of SBFD capable UEs.

In some arrangements of embodiments of the present technique, a deactivated UL sub-band can be used for DL reception. This enables the deactivated frequency resources to be used for traffic for the SBFD UE. Alternatively or additionally, a deactivated DL sub-band can, in some arrangements, be used for UL transmission. In other words, the communications device may be configured, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, to receive, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is an uplink sub-band, downlink signals from the infrastructure equipment, and/or to transmit, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is a downlink sub-band, uplink signals to the infrastructure equipment.

In some arrangements of embodiments of the present technique, the SBFD capable UE interprets subsequent slot format configuration for SBFD OFDM symbols as an activation or deactivation of the guard sub-band it they are configured. That is the guard sub-band is used for transmission or reception depending on the link direction indicated by the subsequent slot format configuration. In other words, the one or more activated sub-band may be guard sub-bands. For example if the subsequent slot format configuration indicates that an SBFD OFDM symbol is DL, the SBFD capable UE may use the guard sub-band (if configured) for DL reception, and if the subsequent slot format configuration indicates that an SBFD OFDM symbols is UL, the SBFD capable UE may use the guard sub-band (if configured) for UL transmission. This recognizes that since a DL or UL sub-band is deactivated the role of the guard sub-band is no longer needed and it is therefore beneficial to use the frequency resources occupied by the guard sub-band for transmission or reception. In some arrangements of embodiments of the present technique, a SBFD capable UE only deactivates a sub-band if the SBFD OFDM symbols are configured on original FL OFDM symbols. In other words, the one or more of the SBFD symbols within which the one or more active sub-bands are deactivated may be (originally configured as) flexible symbols within which the communications device is able to either transmit uplink signals to or receive downlink signals from the communications device. This recognises that legacy subsequent slot format configurations such as SFI and TDD-UL-DL-ConfigDedicated, are used only for FL OFDM symbols and that legacy UEs do not expect non-FL OFDM symbols to be further changed to UL or DL OFDM symbols.

In some arrangements of embodiments of the present technique, the SBFD capable UE interprets subsequent slot format configuration for non-SBFD OFDM symbols, as per legacy behaviour as described above. That is for FL OFDM symbols, the SBFD capable UE will use it as UL, DL or remain as FL OFDM symbols as per the indicated link direction for these FL OFDM symbols in the subsequent slot format configuration. In other words, the first modification may comprise determining that the second pattern overwrites the first pattern for the non-SBFD symbols of the subset.

In some arrangements of embodiments of the present technique the said subsequent slot format configuration is the legacy dynamic SFI. In other words, the second slot format configuration may be a slot format indicator, SFI, and wherein the SFI is received from the infrastructure equipment in a group common downlink control information, GC-DCI, which may be transmitted by the infrastructure equipment to the communications device as well as to one or more other communications devices. The link direction of a SBFD OFDM symbol indicated in the SFI determines whether the UL sub-band or DL sub-band is activated or deactivated. That is, for an SBFD OFDM symbol, if the SFI indicates that this OFDM symbol is DL, then the DL sub-band(s) are activated whilst the UL sub-band is deactivated, and if the SFI indicates that this OFDM symbol is UL, then the UL sub-band is activated whilst the DL subband deactivated.

An example is shown in Figure 13, where the cell specific TDD Slot Format configuration 1301, i.e., using RRC parameter TDD-UL-DL-ConfigCommon, is {DDDSU}, where here the “S” slot i.e., Slot w+3 is fully FL OFDM symbols. The network further configures, with SBFD configuration 1302, SBFD capable UEs in the cell with SBFD Slot Format {XXXSU}, where “X” is an SBFD slot and an “S” slot, i.e., Slot n+3, consists of SBFD OFDM symbols in the first half of the slot and FL OFDM symbols in the remaining half of the slot. The network then transmits a GC-DCI carrying an SFI to a group of UEs consisting of SBFD and legacy UEs in Slot n+2 to dynamically configure the slot format for Slot n+3. The SFI indicates in the example of Figure 13 an index = 28, which correspond to a slot format of \ddddddddddddfu\, where “ ” = DL OFDM symbol, “M” = UL OFDM symbol symbol.

For SBFD capable UEs, since the first 7 OFDM symbols of Slot n+3 are SBFD OFDM symbols, and these OFDM symbols are indicated as DL by the SFI, such SBFD capable UEs deactivate 1310 the UL sub-band, i.e., they refrain from transmitting uplink signals in these OFDM symbols. The remaining OFDM symbols in Slot n+3 were FL OFDM (non-SBFD) symbols and so the SBFD capable UEs follow legacy behaviour and use the eighth to twelfth OFDM symbols as DL, the thirteenth OFDM symbol remains as FL, and the fourteenth (i.e., last) OFDM symbol as UL.

For a legacy UE (by which the SBFD configuration 1302 is not understood or thus applied), Slot n+3 consists of all FL OFDM symbols as the legacy UE cannot be configured with SBFD OFDM symbols and hence it uses them according to the SFI indication, i.e., the first 12 OFDM symbols are DL, the thirteenth OFDM symbol is FL and the last OFDM symbol is UL. Hence, if the legacy UE receives a PDSCH in Slot n+3 on frequencies overlapping those of the UL sub-band of an SBFD capable UE, it would not experience CLI interference from the SBFD capable UE as the UL sub-band in Slot n+ 3 was deactivated 1310 by such a SBFD capable UE.

In some arrangements of embodiments of the present technique the said subsequent slot format configuration is the legacy semi-static UE dedicated slot format configuration which is configured using the RRC parameter TDD-UL-DL-ConfigDedicated. In other words, the second slot format configuration may be a semi-static user equipment, UE, dedicated slot format configuration, and wherein the UE dedicated slot format configuration is received from the infrastructure equipment in RRC signalling. Similarly, to the second/subsequent slot format configuration being an SFI as described above, the link direction of an SBFD OFDM symbol configured by the legacy semi-static UE dedicated slot format configuration indicates that the sub-band with the indicated link direction is active whilst the sub-band with the opposite link direction is deactivated.

An example is shown in Figure 14, where the cell specific TDD Slot Format configuration TDD-UL-DL- ConfigCommon, configures 1401 a slot format {DDDSU}, which is further configured for SBFD operation, e.g., using another RRC configuration 1402, to {XXXSU}. The network signals the legacy semi-static UE dedicated slot configuration TDD-UL-DL-ConfigDedicated to an SBFD capable UE 1403 and to a legacy UE 1404 that configures Slot w+3 to a full UL slot. The legacy UE follows the configuration 1404 from TDD-UL-DL-ConfigDedicated and changes all the FL OFDM symbols in Slot «+3 to UL OFDM symbols. The legacy UE is then scheduled, using an UL Grant, a PUSCH, which is transmitted in Slot w+3.

The SBFD capable UE receiving the legacy semi-static UE dedicated slot format configuration 1403 TDD-UL-DL-ConfigDedicated, interprets it differently for SBFD OFDM symbols and non-SBFD OFDM symbols. For non-SBFD OFDM symbols, i.e., the FL OFDM symbols in the eighth to the fourteenth OFDM symbols of Slot n+3, these are used as UL OFDM symbols. For SBFD OFDM symbols in the first to seventh OFDM symbols of Slot n+3, the DL sub-bands are deactivated 1410; that is the UE only transmits in the UL sub-band and does not expect DL reception in the DL sub-bands, since DL transmissions at the gNB would cause CLI to UL transmissions from legacy UEs.

It should be appreciated that the above-described arrangements of embodiments of the present technique in which the said subsequent slot format configuration is the legacy SFI and legacy TDD-UL-DL- ConfigDedicated, can be implemented together or individually. That is, it may be defined in future specifications that deactivation of sub-bands is only implemented using SFI but not for TDD-UL-DL- ConfigDedicated, and vice-versa. In another implementation, both SFI and TDD-UL-DL- ConfigDedicated may be used to deactivate sub-bands. Arrangements of embodiments of the present technique propose that any appropriate subsequent slot format configuration is able to be used to configure the activation or deactivation (for example) of SBFD sub-bands for SBFD-capable UEs.

In some arrangements of embodiments of the present technique, the said deactivation of a sub-band is to deactivate only a subset of the sub-bands, for cases where there is more than one DL sub-band or UL subband. In other words, the one or more active sub-bands that are deactivated may be a subset of the active sub-bands within the SBFD symbols of the subset, and wherein one or more other active sub-bands within the SBFD symbols of the subset are not deactivated. For example, in Rel-19 SBFD operations, there can be two DL sub-bands in a SBFD OFDM symbol and here for such SBFD frequency configurations, the said deactivation will deactivate only one of the DL sub-bands. Which DL sub-band is to be deactivated is semi-static configured prior to the signalling of the subsequent slot format configuration messages. In some arrangements of embodiments of the present technique, where the said semi-static configuration indicates which subset of sub-bands are deactivated by a subsequent slot format configuration message, the subset of sub-bands that are deactivated are independently configured per subsequent slot format configuration. In other words, the communications device may be configured to receive, from the infrastructure equipment before receiving the second slot format configuration, radio resource control, RRC, signalling or the like, wherein the RRC signalling comprises an indication of the subset of the active sub-bands that is to be deactivated after receiving the second slot format configuration.

The subset of active sub-bands to be deactivated may depend on the type of the subsequent slot format configuration used. For example, for the case where two DL sub-bands are configured, the upper DL sub-band may be configured to be deactivated under an SFI indication, and the lower DL sub-band may be deactivated under the TDD-UL-DL-ConfigDedicated configuration. In another example, both DL subbands are deactivated under SFI indication but only the upper DL sub-band is deactivated under TDD- UL-DL-ConfigDedicated configuration. In other words, the indicated subset of the active sub-bands which is to be deactivated may be dependent on a type of the second slot format configuration. Here, where the subset of sub-bands to be deactivated may be indicated in RRC signalling or defined in the specifications, in respect of the different types of subsequent slot format configuration, multiple indications of different subsets may be provided in this RRC message where each different subset of subbands to be deactivated may each be associated with a different type of subsequent slot format configuration.

In some arrangements of embodiments of the present technique, the SBFD capable UE can be indicated to ignore one or more subsequent slot format configuration messages. This indication may be an indication received from the gNB, or may be fixed in the specifications and thus known by the communications device. That is, the ignored subsequent slot format configuration message will not deactivate any subbands for the SBFD capable UE. In other words, the communications device may be configured to receive, from the infrastructure equipment before receiving the second slot format configuration, an indication that the communications device is to ignore the second modification. That is, the communications device may effectively treat the second modification as having not been made to those SBFD symbols rather than having been changed in accordance with the legacy configuration or that subbands have been activated or deactivated or the like.

For example, the gNB can indicate to a SBFD capable UE to ignore TDD-UL-DL-ConfigDedicated configuration but obey SFI indications and so only SFI indications can deactivate a sub-band. In other words, the indication that the communications device is to ignore the second modification is dependent on a type of the second slot format configuration.

In another example, an SFBD capable UE may be preconfigured (in the specifications) with set behaviour dependent on the type of slot format configuration message; again, it may be configured to ignore TDD- UL-DL-ConfigDedicated configurations but obey SFI indications and so only SFI indications can deactivate a sub-band. In other words, the communications device may be configured to determine, dependent on a type of the second slot format configuration, that the communications device is to ignore the second modification.

In some arrangements of embodiments of the present technique, a deactivated sub-band is re-activated by a (another) subsequent slot format configuration, for example if the subsequent slot format indicates that the OFDM symbol(s) is a FL OFDM symbol(s). In other words, the communications device may be configured to receive, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more deactivated sub-bands is to be reactivated if the at least one of the one or more deactivated sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

An example is shown in Figure 15, where an SBFD capable UE is configured 1501 with SBFD format {XXXSU} from original slot format {DDDSU}. It later receives a subsequent slot format configuration 1502, such as TDD-UL-DL-ConfigDedicated configuration, that configures 1503 the “5” slot to a full UL slot; that is, Slot w+3 is indicated as folly UL. Consequently, the DL sub-bands in the “S” slot, i.e., Slot «+3, are deactivated 1510. At a later time, the SBFD capable UE is configured by another TDD-UL-DL- ConfigDedicated configuration 1504 to change the “S” slot back to folly FL; that is Slot m+3 (where m>n) is converted back 1520 to folly FL OFDM symbols. Consequently, as per such arrangements, the previously deactivated 1510 DL sub-bands in the “S” slot, e.g., Slot m+3, are reactivated 1520.

In some arrangements of embodiments of the present technique, an activated guard sub-band is deactivated by a (another) subsequent slot format configuration, for example if the subsequent slot format indicates that the OFDM symbol(s) is a FL OFDM symbol(s). A deactivated guard sub-band means that the guard sub-band functions as its original intention, i.e., act as a frequency gap to reduce CLI by not using it for DL reception or UL transmission. In other words, the communications device may be configured to receive, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more activated guard sub-bands is to be deactivated if the at least one of the one or more activated guard sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

In some arrangements of embodiments of the present technique, when a deactivated sub-band is reactivated, any activated guard sub-band (if any) is deactivated, i.e., the activated guard sub-band that is used for DL or UL returns to its original purpose, i.e. not used for DL or UL. In other words, the communications device may be configured to determine that one or more deactivated sub-bands are to be reactivated if the one or more deactivated sub-bands are within one or more of the SBFD symbols of the at least the part of the subset, and to determine that the at least one activated guard sub-band is to be deactivated if the at least one activated guard sub-band is within one or more of the SBFD symbols of the at least the part of the subset.

In some arrangements of embodiments of the present technique, a deactivated sub-band is deactivated for a fixed period of time. That is, after receiving a subsequent slot format configuration where one or more sub-bands are deactivated, the SBFD capable UE will reactivate the one or more deactivated sub-bands after the said fixed period of time. In other words, the communications device may be configured, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, to determine that the one or more deactivated sub-bands are to be deactivated for a configured time period, and to determine, after the configured time period, that the one or more deactivated sub-bands are reactivated The period of time where a sub-band is deactivated can be dynamically indicated using a DCI, semi-statically configured or fixed in the specifications. In some arrangements of embodiments of the present technique, an activated guard sub-band is activated for a fixed period of time. That is, after receiving a subsequent slot format configuration where one or more guard sub-bands are activated, the SBFD capable UE will deactivate the one or more activated guard sub-bands after the said fixed period of time. In other words, the communications device may be configured, after the one or more guard sub-bands within one or more of the SBFD symbols of the subset are activated, to determine that the one or more activated guard sub-bands are to be activated for a configured time period, and to determine, after the configured time period, that the one or more activated guard sub-bands are deactivated. The period of time where a guard sub-band is activated can be dynamically indicated using a DCI, semi-statically configured or fixed in the specifications.

Figure 16 shows a flow diagram illustrating an example process of communications in a communications system in accordance with embodiments of the present technique. The process shown by Figure 16 is specifically a method of operating a communications device (e.g. UE) configured to transmit signals to and/or to receive signals from an infrastructure equipment (e.g. a gNB) of a wireless communications network.

The method begins in step SI. The method comprises, in step S2, receiving, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time- divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non- SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time- divided slots. In step S3, the process comprises receiving, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non- SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols. The process then comprises, in step S4, determining, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, while in step S5, the method comprises determining, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, where here, the first modification and the second modification are different. The process ends in step S6.

Those skilled in the art would appreciate that the method shown by Figure 16 may be adapted in accordance with embodiments of the present technique. For example, other intermediate steps may be included in such a method, or the steps may be performed in any logical order. Though embodiments of the present technique have been described largely by way of the example communications system shown in Figure 12, and further by way of the implementation examples shown in Figures 13 to 15, it would be clear to those skilled in the art that they could be equally applied to other systems to those described herein, provided that these are within the scope of the claims.

Those skilled in the art would further appreciate that such infrastructure equipment and/or communications devices as herein defined may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. It would be further appreciated by those skilled in the art that such infrastructure equipment and communications devices as herein defined and described may form part of communications systems other than those defined by the present disclosure, provided that these are within the scope of the claims. The following numbered paragraphs provide further example aspects and features of the present technique:

Paragraph 1. A method of operating a communications device configured to transmit signals to and/or to receive signals from an infrastructure equipment of a wireless communications network, the method comprising receiving, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, receiving, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, determining, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and determining, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Paragraph 2. A method according to Paragraph 1, wherein the second modification comprises one or more sub-bands within one or more of the SBFD symbols of the subset being activated.

Paragraph 3. A method according to Paragraph 2, wherein the method comprises, after the one or more sub-bands within one or more of the SBFD symbols of the subset are activated, transmitting, in at least one of the activated sub-bands if the at least one activated sub-band is an uplink sub-band, uplink signals to the infrastructure equipment, and/or receiving, in at least one of the activated sub-bands if the at least one activated sub-band is a downlink sub-band, downlink signals from the infrastructure equipment.

Paragraph 4. A method according to Paragraph 2 or Paragraph 3, wherein the one or more activated sub-band are guard sub-bands.

Paragraph 5. A method according to Paragraph 4, comprising receiving, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more activated guard sub-bands is to be deactivated if the at least one of the one or more activated guard sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

Paragraph 6. A method according to Paragraph 5, comprising determining that one or more deactivated sub-bands are to be reactivated if the one or more deactivated sub-bands are within one or more of the SBFD symbols of the at least the part of the subset, and determining that the at least one activated guard sub-band is to be deactivated if the at least one activated guard sub-band is within one or more of the SBFD symbols of the at least the part of the subset. Paragraph 7. A method according to any of Paragraphs 4 to 6, wherein the method comprises, after the one or more guard sub-bands within one or more of the SBFD symbols of the subset are activated, determining that the one or more activated guard sub-bands are to be activated for a configured time period, and determining, after the configured time period, that the one or more activated guard sub-bands are deactivated.

Paragraph 8. A method according to any of Paragraphs 1 to 7, wherein the second modification comprises one or more active sub-bands within one or more of the SBFD symbols of the subset being deactivated.

Paragraph 9. A method according to Paragraph 8, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, transmitting uplink signals to and/or receiving downlink signals from the infrastructure equipment only in radio resources of the one or more time-divided slots that are outside of the one or more deactivated sub-bands.

Paragraph 10. A method according to Paragraph 8 or Paragraph 9, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, receiving, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is an uplink sub-band, downlink signals from the infrastructure equipment, and/or transmitting, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is a downlink sub-band, uplink signals to the infrastructure equipment.

Paragraph 11. A method according to any of Paragraphs 8 to 10, wherein the one or more of the SBFD symbols within which the one or more active sub-bands are deactivated are configured on flexible symbols within which the communications device is able to either transmit uplink signals to or receive downlink signals from the communications device.

Paragraph 12. A method according to any of Paragraphs 8 to 11, wherein the one or more active subbands that are deactivated is a subset of the active sub-bands within the SBFD symbols of the subset, and wherein one or more other active sub-bands within the SBFD symbols of the subset are not deactivated.

Paragraph 13. A method according to Paragraph 12, comprising receiving, from the infrastructure equipment before receiving the second slot format configuration, radio resource control, RRC, signalling, wherein the RRC signalling comprises an indication of the subset of the active sub-bands that is to be deactivated after receiving the second slot format configuration.

Paragraph 14. A method according to Paragraph 13, wherein the indicated subset of the active subbands which is to be deactivated is dependent on a type of the second slot format configuration.

Paragraph 15. A method according to any of Paragraphs 8 to 14, comprising receiving, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more deactivated sub-bands is to be reactivated if the at least one of the one or more deactivated subbands is within one or more of the SBFD symbols of the at least the part of the subset.

Paragraph 16. A method according to any of Paragraphs 8 to 15, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, determining that the one or more deactivated sub-bands are to be deactivated for a configured time period, and determining, after the configured time period, that the one or more deactivated sub-bands are reactivated.

Paragraph 17. A method according to any of Paragraphs 1 to 16, comprising receiving, from the infrastructure equipment before receiving the second slot format configuration, an indication that the communications device is to ignore the second modification. Paragraph 18. A method according to Paragraph 17, wherein the indication that the communications device is to ignore the second modification is dependent on a type of the second slot format configuration. Paragraph 19. A method according to any of Paragraphs 1 to 18, comprising determining, dependent on a type of the second slot format configuration, that the communications device is to ignore the second modification.

Paragraph 20. A method according to any of Paragraphs 1 to 19, wherein the first modification comprises determining that the second pattern overwrites the first pattern for the non-SBFD symbols of the subset.

Paragraph 21. A method according to any of Paragraphs 1 to 20, wherein the second slot format configuration is a slot format indicator, SFI, and wherein the SFI is received from the infrastructure equipment in a group common downlink control information, GC-DCI.

Paragraph 22. A method according to any of Paragraphs 1 to 21, wherein the second slot format configuration is a semi-static user equipment, UE, dedicated slot format configuration, and wherein the UE dedicated slot format configuration is received from the infrastructure equipment in RRC signalling. Paragraph 23. A communications device comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a wireless communications network, and controller circuitry configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to receive, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to determine, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to determine, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different. Paragraph 24. Circuitry for a communications device, the circuitry comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a wireless communications network, and controller circuitry configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to receive, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to determine, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to determine, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different. Paragraph 25. A method of operating an infrastructure equipment forming part of a wireless communications network, the method comprising transmitting, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, transmitting, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, performing, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and performing, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Paragraph 26. A method according to Paragraph 25, wherein the second modification comprises one or more sub-bands within one or more of the SBFD symbols of the subset being activated.

Paragraph 27. A method according to Paragraph 26, wherein the method comprises, after the one or more sub-bands within one or more of the SBFD symbols of the subset are activated, receiving, in at least one of the activated sub-bands if the at least one activated sub-band is an uplink sub-band, uplink signals from the communications device, and/or transmitting, in at least one of the activated sub-bands if the at least one activated sub-band is a downlink sub-band, downlink signals to the communications device.

Paragraph 28. A method according to Paragraph 26 or Paragraph 27, wherein the one or more activated sub-band are guard sub-bands.

Paragraph 29. A method according to Paragraph 28, comprising transmitting, to the communications device, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and deactivating, based on transmitting the third slot format configuration, at least one of the one or more activated guard sub-bands if the at least one of the one or more activated guard sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

Paragraph 30. A method according to Paragraph 29, comprising reactivating one or more deactivated sub-bands if the one or more deactivated sub-bands are within one or more of the SBFD symbols of the at least the part of the subset, and deactivating the at least one activated guard sub-band if the at least one activated guard sub-band is within one or more of the SBFD symbols of the at least the part of the subset.

Paragraph 31. A method according to any of Paragraphs 28 to 30, wherein the method comprises, after the one or more guard sub-bands within one or more of the SBFD symbols of the subset are activated, determining that the one or more activated guard sub-bands are to be activated for a configured time period, and deactivating the one or more activated guard sub-bands after the configured time period.

Paragraph 32. A method according to any of Paragraphs 25 to 31, wherein the second modification comprises one or more active sub-bands within one or more of the SBFD symbols of the subset being deactivated.

Paragraph 33. A method according to Paragraph 32, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, receiving uplink signals from and/or transmitting downlink signals to the communications device only in radio resources of the one or more time-divided slots that are outside of the one or more deactivated sub-bands. Paragraph 34. A method according to Paragraph 32 or Paragraph 33, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, transmitting, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is an uplink sub-band, downlink signals to the communications device, and/or receiving, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is a downlink sub-band, uplink signals from the communications device.

Paragraph 35. A method according to any of Paragraphs 32 to 34, wherein the one or more of the SBFD symbols within which the one or more active sub-bands are deactivated are configured on flexible symbols within which the infrastructure equipment is able to either receive uplink signals from or transmit downlink signals to the communications device.

Paragraph 36. A method according to any of Paragraphs 32 to 35, wherein the one or more active subbands that are deactivated is a subset of the active sub-bands within the SBFD symbols of the subset, and wherein one or more other active sub-bands within the SBFD symbols of the subset are not deactivated. Paragraph 37. A method according to Paragraph 36, comprising transmitting, to the communications device before transmitting the second slot format configuration, radio resource control, RRC, signalling, wherein the RRC signalling comprises an indication of the subset of the active sub-bands that is to be deactivated after receiving the second slot format configuration.

Paragraph 38. A method according to Paragraph 37, wherein the indicated subset of the active subbands which is to be deactivated is dependent on a type of the second slot format configuration.

Paragraph 39. A method according to any of Paragraphs 32 to 38, comprising transmitting, to the communications device, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and reactivating, based the third slot format configuration, at least one of the one or more deactivated sub-bands if the at least one of the one or more deactivated sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

Paragraph 40. A method according to any of Paragraphs 32 to 39, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, determining that the one or more deactivated sub-bands are to be deactivated for a configured time period, and reactivating, after the configured time period, the one or more deactivated sub-bands. Paragraph 41. A method according to any of Paragraphs 25 to 40, comprising transmitting, to the communications device before transmitting the second slot format configuration, an indication that the communications device is to ignore the second modification. Paragraph 42. A method according to Paragraph 41, wherein the indication that the communications device is to ignore the second modification is dependent on a type of the second slot format configuration. Paragraph 43. A method according to any of Paragraphs 25 to 42, wherein the first modification comprises the second pattern overwriting the first pattern for the non-SBFD symbols of the subset. Paragraph 44. A method according to any of Paragraphs 25 to 43, wherein the second slot format configuration is a slot format indicator, SFI, and wherein the SFI is transmitted to the communications device in a group common downlink control information, GC-DCI.

Paragraph 45. A method according to any of Paragraphs 25 to 44, wherein the second slot format configuration is a semi-static user equipment, UE, dedicated slot format configuration, and wherein the UE dedicated slot format configuration is transmitted to the communications device in RRC signalling. Paragraph 46. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a communications device, and controller circuitry configured in combination with the transceiver circuitry to transmit, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to transmit, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to perform, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to perform, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different. Paragraph 47. Circuitry for an infrastructure equipment forming part of a wireless communications network, the circuitry comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a communications device, and controller circuitry configured in combination with the transceiver circuitry to transmit, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to transmit, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to perform, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to perform, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

Paragraph 48. A wireless communications system comprising a communications device according to Paragraph 23 and an infrastructure equipment according to Paragraph 46.

Paragraph 49. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to any of Paragraphs 1 to 22 or any of Paragraphs 25 to 45.

Paragraph 50. A non-transitory computer-readable storage medium storing a computer program according to Paragraph 49.

It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and/or processors may be used without detracting from the embodiments.

Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

References

[1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009. [2] TR 38.913, “3^rd Generation Partnership Project; Technical Specification Group Radio Access

Network; Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)”, 3GPP, vl4.3.0, August 2017.

[3] RP-213591, “New SI: Study on evolution of NR duplex operation,” CMCC, RAN#94e,

December 2021. [4] RP-220633, “Revised SID: Study on evolution of NR duplex operation,” CMCC, RAN#95e,

March 2022.

[5] European Patent No. 3545716.

[6] TS 38.213, “3^rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical layer procedures for control (Release 18),” 3GPP, v 18. 1.0, December 2023.

Claims

CLAIMS What is claimed is:

1. A method of operating a communications device configured to transmit signals to and/or to receive signals from an infrastructure equipment of a wireless communications network, the method comprising receiving, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, receiving, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, determining, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and determining, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

2. A method according to Claim 1, wherein the second modification comprises one or more subbands within one or more of the SBFD symbols of the subset being activated.

3. A method according to Claim 2, wherein the method comprises, after the one or more sub-bands within one or more of the SBFD symbols of the subset are activated, transmitting, in at least one of the activated sub-bands if the at least one activated sub-band is an uplink sub-band, uplink signals to the infrastructure equipment, and/or receiving, in at least one of the activated sub-bands if the at least one activated sub-band is a downlink sub-band, downlink signals from the infrastructure equipment.

4. A method according to Claim 2, wherein the one or more activated sub-band are guard sub-bands.

5. A method according to Claim 4, comprising receiving, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more activated guard sub-bands is to be deactivated if the at least one of the one or more activated guard sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

6. A method according to Claim 5, comprising determining that one or more deactivated sub-bands are to be reactivated if the one or more deactivated sub-bands are within one or more of the SBFD symbols of the at least the part of the subset, and determining that the at least one activated guard sub-band is to be deactivated if the at least one activated guard sub-band is within one or more of the SBFD symbols of the at least the part of the subset.

7. A method according to Claim 4, wherein the method comprises, after the one or more guard subbands within one or more of the SBFD symbols of the subset are activated, determining that the one or more activated guard sub-bands are to be activated for a configured time period, and determining, after the configured time period, that the one or more activated guard sub-bands are deactivated.

8. A method according to Claim 1, wherein the second modification comprises one or more active sub-bands within one or more of the SBFD symbols of the subset being deactivated.

9. A method according to Claim 8, wherein the method comprises, after the one or more active subbands within one or more of the SBFD symbols of the subset are deactivated, transmitting uplink signals to and/or receiving downlink signals from the infrastructure equipment only in radio resources of the one or more time-divided slots that are outside of the one or more deactivated sub-bands.

10. A method according to Claim 8, wherein the method comprises, after the one or more active subbands within one or more of the SBFD symbols of the subset are deactivated, receiving, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is an uplink sub-band, downlink signals from the infrastructure equipment, and/or transmitting, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is a downlink sub-band, uplink signals to the infrastructure equipment.

11. A method according to Claim 8, wherein the one or more of the SBFD symbols within which the one or more active sub-bands are deactivated are configured on flexible symbols within which the communications device is able to either transmit uplink signals to or receive downlink signals from the communications device.

12. A method according to Claim 8, wherein the one or more active sub-bands that are deactivated is a subset of the active sub-bands within the SBFD symbols of the subset, and wherein one or more other active sub-bands within the SBFD symbols of the subset are not deactivated.

13. A method according to Claim 12, comprising receiving, from the infrastructure equipment before receiving the second slot format configuration, radio resource control, RRC, signalling, wherein the RRC signalling comprises an indication of the subset of the active sub-bands that is to be deactivated after receiving the second slot format configuration.

14. A method according to Claim 13, wherein the indicated subset of the active sub-bands which is to be deactivated is dependent on a type of the second slot format configuration.

15. A method according to Claim 8, comprising receiving, from the infrastructure equipment, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and determining, based on receiving the third slot format configuration, that at least one of the one or more deactivated sub-bands is to be reactivated if the at least one of the one or more deactivated subbands is within one or more of the SBFD symbols of the at least the part of the subset.

16. A method according to Claim 8, wherein the method comprises, after the one or more active subbands within one or more of the SBFD symbols of the subset are deactivated, determining that the one or more deactivated sub-bands are to be deactivated for a configured time period, and determining, after the configured time period, that the one or more deactivated sub-bands are reactivated.

17. A method according to Claim 1, comprising receiving, from the infrastructure equipment before receiving the second slot format configuration, an indication that the communications device is to ignore the second modification.

18. A method according to Claim 17, wherein the indication that the communications device is to ignore the second modification is dependent on a type of the second slot format configuration.

19. A method according to Claim 1, comprising determining, dependent on a type of the second slot format configuration, that the communications device is to ignore the second modification.

20. A method according to Claim 1, wherein the first modification comprises determining that the second pattern overwrites the first pattern for the non-SBFD symbols of the subset.

21. A method according to Claim 1, wherein the second slot format configuration is a slot format indicator, SFI, and wherein the SFI is received from the infrastructure equipment in a group common downlink control information, GC-DCI.

22. A method according to Claim 1, wherein the second slot format configuration is a semi-static user equipment, UE, dedicated slot format configuration, and wherein the UE dedicated slot format configuration is received from the infrastructure equipment in RRC signalling.

23. A communications device comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a wireless communications network, and controller circuitry configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to receive, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to determine, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to determine, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

24. Circuitry for a communications device, the circuitry comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a wireless communications network, and controller circuitry configured in combination with the transceiver circuitry to receive, from the infrastructure equipment, a first slot format configuration for one or more time-divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to receive, from the infrastructure equipment, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to determine, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to determine, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

25. A method of operating an infrastructure equipment forming part of a wireless communications network, the method comprising transmitting, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, transmitting, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, performing, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and performing, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

26. A method according to Claim 25, wherein the second modification comprises one or more subbands within one or more of the SBFD symbols of the subset being activated.

27. A method according to Claim 26, wherein the method comprises, after the one or more sub-bands within one or more of the SBFD symbols of the subset are activated, receiving, in at least one of the activated sub-bands if the at least one activated sub-band is an uplink sub-band, uplink signals from the communications device, and/or transmitting, in at least one of the activated sub-bands if the at least one activated sub-band is a downlink sub-band, downlink signals to the communications device.

28. A method according to Claim 26, wherein the one or more activated sub-band are guard subbands.

29. A method according to Claim 28, comprising transmitting, to the communications device, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and deactivating, based on transmitting the third slot format configuration, at least one of the one or more activated guard sub-bands if the at least one of the one or more activated guard sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

30. A method according to Claim 29, comprising reactivating one or more deactivated sub-bands if the one or more deactivated sub-bands are within one or more of the SBFD symbols of the at least the part of the subset, and deactivating the at least one activated guard sub-band if the at least one activated guard sub-band is within one or more of the SBFD symbols of the at least the part of the subset.

31. A method according to Claim 28, wherein the method comprises, after the one or more guard sub-bands within one or more of the SBFD symbols of the subset are activated, determining that the one or more activated guard sub-bands are to be activated for a configured time period, and deactivating the one or more activated guard sub-bands after the configured time period.

32. A method according to Claim 25, wherein the second modification comprises one or more active sub-bands within one or more of the SBFD symbols of the subset being deactivated.

33. A method according to Claim 32, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, receiving uplink signals from and/or transmitting downlink signals to the communications device only in radio resources of the one or more time-divided slots that are outside of the one or more deactivated sub-bands.

34. A method according to Claim 32, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, transmitting, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is an uplink sub-band, downlink signals to the communications device, and/or receiving, in at least one of the deactivated sub-bands if the at least one deactivated sub-band is a downlink sub-band, uplink signals from the communications device.

35. A method according to Claim 32, wherein the one or more of the SBFD symbols within which the one or more active sub-bands are deactivated are configured on flexible symbols within which the infrastructure equipment is able to either receive uplink signals from or transmit downlink signals to the communications device.

36. A method according to Claim 32, wherein the one or more active sub-bands that are deactivated is a subset of the active sub-bands within the SBFD symbols of the subset, and wherein one or more other active sub-bands within the SBFD symbols of the subset are not deactivated.

37. A method according to Claim 36, comprising transmitting, to the communications device before transmitting the second slot format configuration, radio resource control, RRC, signalling, wherein the RRC signalling comprises an indication of the subset of the active sub-bands that is to be deactivated after receiving the second slot format configuration.

38. A method according to Claim 37, wherein the indicated subset of the active sub-bands which is to be deactivated is dependent on a type of the second slot format configuration.

39. A method according to Claim 32, comprising transmitting, to the communications device, a third slot format configuration indicating a third pattern for at least part of the subset of the SBFD symbols and/or the non-SBFD symbols, wherein the third pattern is different to the second pattern for the at least the part of the subset of the SBFD symbols and/or the non-SBFD symbols, and reactivating, based the third slot format configuration, at least one of the one or more deactivated sub-bands if the at least one of the one or more deactivated sub-bands is within one or more of the SBFD symbols of the at least the part of the subset.

40. A method according to Claim 32, wherein the method comprises, after the one or more active sub-bands within one or more of the SBFD symbols of the subset are deactivated, determining that the one or more deactivated sub-bands are to be deactivated for a configured time period, and reactivating, after the configured time period, the one or more deactivated sub-bands.

41. A method according to Claim 25, comprising transmitting, to the communications device before transmitting the second slot format configuration, an indication that the communications device is to ignore the second modification.

42. A method according to Claim 41, wherein the indication that the communications device is to ignore the second modification is dependent on a type of the second slot format configuration.

43. A method according to Claim 25, wherein the first modification comprises the second pattern overwriting the first pattern for the non-SBFD symbols of the subset.

44. A method according to Claim 25, wherein the second slot format configuration is a slot format indicator, SFI, and wherein the SFI is transmitted to the communications device in a group common downlink control information, GC-DCI.

45. A method according to Claim 25, wherein the second slot format configuration is a semi-static user equipment, UE, dedicated slot format configuration, and wherein the UE dedicated slot format configuration is transmitted to the communications device in RRC signalling.

46. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a communications device, and controller circuitry configured in combination with the transceiver circuitry to transmit, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to transmit, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to perform, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to perform, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

47. Circuitry for an infrastructure equipment forming part of a wireless communications network, the circuitry comprising transceiver circuitry configured to transmit signals to and/or to receive signals from a communications device, and controller circuitry configured in combination with the transceiver circuitry to transmit, to the communications device, a first slot format configuration for one or more time- divided slots of a radio access interface between the communications device and the infrastructure equipment, wherein the one or more time-divided slots each comprise one or more sub-band full duplex, SBFD, symbols and/or one or more non-SBFD symbols, and wherein the first slot format configuration indicates a first pattern for the SBFD symbols of the one or more time-divided slots and/or the non-SBFD symbols of the one or more time-divided slots, to transmit, to the communications device, a second slot format configuration indicating a second pattern for a subset of the SBFD symbols and/or the non-SBFD symbols, wherein the second pattern is different to the first pattern for the subset of the SBFD symbols and/or the non-SBFD symbols, to perform, based on the second slot format configuration, a first modification of the non-SBFD symbols of the subset, and to perform, based on the second slot format configuration, a second modification of the SBFD symbols of the subset, wherein the first modification and the second modification are different.

48. A wireless communications system comprising a communications device according to Claim 23 and an infrastructure equipment according to Claim 46.

49. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to Claim 1 or Claim 25.

50. A non-transitory computer-readable storage medium storing a computer program according to Claim 49.