CN104168610B - The method, apparatus and terminal device of a kind of transmission of downlink signal - Google Patents

Abstract

The invention discloses a method, device and terminal equipment for transmitting downlink reference signals, which can increase the amount of resources used for transmitting CSI-RS without affecting system performance. Wherein, the method includes: reserving REs in resource elements RE used for transmission of downlink demodulation reference signal DM-RS; The channel state information reference signal CSI‑RS is transmitted on the data RE.

Description

A method, device and terminal equipment for transmitting downlink signals

technical field

The present invention relates to the technical field of wireless communication, in particular to a method, device and terminal equipment for transmitting downlink signals.

Background technique

After a long period of development, the cellular mobile communication system has developed into the 4th generation (4G) wireless communication system. The cellular mobile communication system represented by the Term Evolution-Advanced) communication system has completed the eleventh version (also called Rel-11), and is currently working on the twelfth version (Rel-12) research stage.

In the LTE-A Rel-12 protocol, small cell enhancement is a direction that attracts attention. In the small cell enhancement technology, a low power node (LPN, Low Power Node) is used to provide greater capacity network coverage for hotspot areas and indoors. Since the coverage range of the LPN is usually around 20-40 meters, in a co-frequency scenario where the number of terminal devices (UE, UserEquipment) is relatively dense, within a small range (for example, within a radius of 100 meters), Multiple LPNs are deployed. However, the deployment of a large number of LPNs in a concentrated area will bring about large co-channel interference between sites. Moreover, due to the characteristics of multiple bursts and strong randomness of mobile broadband communication services, the fluctuation of interference will be more intense than that of traditional voice-based communication methods. Therefore, in the scenario where co-frequency dense small cells are deployed, how the UE eliminates the impact of fluctuating co-channel interference so as to implement effective measurement of channel state information (CSI, Channel State Information) of the serving cell is a relatively important issue.

In the prior art, the UE performs CSI measurement by using a CSI reference signal (CSI-RS, CSI ReferenceSignal). The CSI-RS may include a zero-power CSI-RS for interference measurement and a non-zero power CSI-RS for interference measurement. As shown in FIG. 1 , it is the mapping of CSI-RS in one subframe. Under normal (normal) cyclic prefix (CP, Cyclic Prefix) conditions, in the time domain, the CSI-RS occupies symbols 5 and 6 on even slots and symbols 2 and 3 on odd slots; in the frequency domain In the above, CSI-RS occupies 2 resource units (RE, Resource Element) in each physical resource block (PRB, PhysicalResource Block), and on the entire system bandwidth in the frequency domain, each RB uses the same way mapped.

Wherein, each zero-power CSI-RS needs to occupy 4 CSI-RS antenna ports for transmission, and in the existing agreement, the zero-power CSI-RS is configured as a 4-port CSI-RS. It is defined in the existing protocol that the CSI-RS has up to 8 different antenna ports. Each CSI-RS antenna port occupies 2 RE transmissions in 12 subcarriers in a transmission time interval (TTI, Transmission TimeInterval), 2 CSI-RS antenna ports need to occupy 2 REs for transmission, 4 CSI-RS Antenna ports need to occupy 4 REs for transmission, and 8 CSI-RS antenna ports need to occupy 8 REs for transmission.

The CSI-RS signal transmission in the prior art is introduced in the Rel-10 protocol version, and needs to occupy every PRB in the entire system bandwidth during transmission. In a wireless communication system, with the continuous development of technology, the system includes UEs that comply with different versions of the protocol. For example, the wireless communication system includes UEs that comply with Rel-10 and later protocol versions, and may also include UEs that comply with Rel-10 UEs of previous protocol versions. When introducing CSI-RS for CSI measurement, for UEs complying with different protocol versions, when transmitting CSI-RI, they correspond to different transmission methods:

For the UE that complies with the protocol version before Rel-10, the corresponding number of REs will be knocked out on each PRB by punching holes, which will knock out the encoded data that has been sent, so it will make it comply with the previous protocol of Rel-10 version of the UE with degraded performance. However, for UEs complying with protocol versions after Rel-10, the resources required for transmitting CSI-RS will be reserved in a rate matching manner. Among them, the rate matching means that during resource allocation, data is not mapped to the resource position occupied by the CSI-RS, and when calculating the transmittable resources occupied by the data to be transmitted, it is calculated after removing the resources occupied by the transmission CSI-RS. The rate matching method will reduce the number of available resources for UEs that comply with Rel-10 and protocol versions after Rel-10, and can increase the coding rate of the data to be sent, thereby reducing the number of UEs that comply with Rel-10 and Rel-10. Decoding performance after demodulation of received data by the UE of the later protocol version. When the number of configured sending CSI-RS ports increases, the number of occupied REs also increases correspondingly, thereby having a greater impact on the demodulation performance of the UE.

To sum up, the methods for transmitting downlink reference signals proposed in the prior art will affect UE performance for UEs complying with Rel-11 and protocol versions before Rel-11 when CSI-RS is used to implement CSI. For example, the more antenna ports are configured, the greater the impact on UE performance will be. Secondly, in the scenario of dense LPN deployment, according to the provisions of the existing protocol, the resources for transmitting CSI-RS are not enough.

Contents of the invention

Embodiments of the present invention provide a method, device and terminal equipment for transmitting downlink reference signals, which can increase the number of resources used for transmitting CSI-RS without affecting system performance.

In the first aspect of the present invention, a method for transmitting downlink signals is provided, including: reserving REs in resource units RE used for transmitting downlink demodulation reference signals DM-RS; on the reserved REs, or on The channel state information reference signal CSI-RS is transmitted on the reserved REs and on the REs used for transmitting downlink data.

With reference to the first aspect of the present invention, in a first possible implementation manner, the method further includes: transmitting the DM-RS and/or the CSI-RS on the REs except the reserved REs among the REs used for transmitting the DM-RS.

In combination with the first aspect of the present invention, the first possible implementation manner, in the second possible implementation manner, further includes: sending an indication message to the UE, where the indication message is used to indicate the transmission of the CSI-RS and/or and transmitting the RE information of the DM-RS.

In combination with the first aspect of the present invention, in a third possible implementation manner, transmitting the CSI-RS on the reserved REs, or on the reserved REs and the REs used to transmit downlink data, includes: : Transmit CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and REs used to transmit downlink data, and select a preset number of REs on the selected REs transmit the CSI-RS sent to the UE, the preset number is less than or equal to the number of reserved REs.

In combination with the first aspect of the present invention, in a fourth possible implementation manner, reserving REs in REs used to transmit DM-RSs includes: including in the subbands configured for the UE to transmit DM-RSs Reserve REs in the REs of the RS; and/or when sending a downlink reference signal to the UE and other at least one UE occupying a different part of the system bandwidth, the subband used for transmission of the downlink contained in the subband of the other at least one UE REs are reserved in REs for data.

In combination with the first aspect of the present invention, in the fourth possible implementation manner, in the fifth possible implementation manner, in the REs used to transmit downlink data included in the subband of the other at least one UE, reserve The RE includes: reserving REs in the REs used to transmit downlink data included in the subband of the other at least one UE based on puncturing or rate matching.

In combination with the first aspect of the present invention, in the fourth possible implementation manner, in the sixth possible implementation manner, in the subband configured for the UE, each physical resource block PRB contains the The number of REs reserved in the REs of the RS is the same as the number of REs reserved in the REs used to transmit downlink data included in each PRB in the subband of the other UE.

In combination with the first aspect of the present invention, any one of the above possible implementation manners, in the seventh possible implementation manner, reserving REs in REs used to transmit DM-RSs includes: Among each pair of REs, at least one pair of REs is reserved, where each pair of REs refers to two REs that occupy the same frequency domain and are adjacent in the time domain.

In combination with the first aspect of the present invention, any one of the above possible implementation manners, in the eighth possible implementation manner, on the reserved REs, or on the reserved REs and used to transmit downlink The transmission of the CSI-RS on the data RE includes: periodically configuring and transmitting the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data.

In combination with the first aspect of the present invention and the second possible implementation manner, in the ninth possible implementation manner, the indication message is further used to indicate that the UE receives at least one subframe after receiving the indication message In the method, the CSI-RS and/or the transmitted DM-RS are obtained on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data.

The second aspect of the present invention provides a method for transmitting downlink signals, including: a terminal device obtains REs reserved by the network side in resource elements RE for transmitting downlink demodulation reference signals DM-RS; The channel state information reference signal CSI-RS is obtained on the RE, or on the reserved RE and the RE used for transmitting downlink data.

With reference to the second aspect of the present invention, in the first possible implementation manner, it further includes: the terminal device obtains the DM-RS and/or CSI- RS.

In combination with the second aspect of the present invention, the first possible implementation manner, in the second possible implementation manner, before the terminal device obtains the REs reserved by the network side in the REs used to transmit the DM-RS, it further includes: the terminal The device receives an indication message from the network side for indicating the information of the RE for transmitting the CSI-RS and/or for transmitting the DM-RS; the terminal device obtains the information reserved by the network side in the RE for transmitting the DM-RS The REs include: the terminal device obtains the REs reserved by the network side in the REs used to transmit the DM-RS according to the received indication message; on the reserved REs, or on the reserved REs Obtaining the CSI-RS on the RE and the RE used to transmit downlink data includes: the terminal device, according to the received indication message, on the reserved RE, or on the reserved RE and for The CSI-RS and/or the DM-RS are obtained from the RE transmitting the downlink data.

In combination with the second aspect of the present invention, in a third possible implementation manner, obtaining a CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data includes: : Obtain CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and REs used to transmit downlink data, and select a preset number of REs on the selected REs The CSI-RS sent from the network side is obtained, and the preset number is less than or equal to the number of reserved REs.

In combination with the second aspect of the present invention, in any one of the above possible ways, in the fourth possible implementation way, on the reserved RE, or on the reserved RE and used for downlink transmission Transmitting the CSI-RS on the data RE includes: periodically obtaining the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data.

In combination with the second aspect of the present invention, in the second possible manner above, in the fifth possible implementation manner, the terminal device, according to the received indication message, performs Obtaining the CSI-RS on the reserved RE and the RE used for transmitting downlink data includes: in at least one subframe after receiving the indication message, according to the received indication message in the reserved Obtain the CSI-RS and/or obtain the DM-RS on the above RE, or on the reserved RE and the RE used for transmitting downlink data.

According to the third aspect of the present invention, a device for transmitting downlink signals is provided, including: a reservation unit, configured to reserve REs in resource elements RE used for transmitting downlink demodulation reference signals DM-RS, and use the reserved The RE is transmitted to the transmission unit; the transmission unit is used for transmitting on the reserved REs according to the reserved REs transmitted by the reservation unit, or on the reserved REs and the REs used to transmit downlink data Channel State Information Reference Signal CSI-RS.

With reference to the third aspect of the present invention, in a first possible implementation manner, the transmission unit is further configured to transmit DM-RSs and/or or CSI-RS.

With reference to the third aspect of the present invention, the first possible implementation manner, in the second possible implementation manner, the transmission unit is further configured to send an indication message to the UE, where the indication message is used to indicate to transmit the CSI - Information about the RS and/or the RE transmitting the DM-RS.

With reference to the third aspect of the present invention, in a third possible implementation manner, the transmission unit is specifically configured to transmit the CSI-RS on some or all of the reserved REs, or transmit the CSI-RS on the reserved REs and use Select a preset number of REs on the REs that transmit downlink data, and transmit the CSI-RS sent to the UE on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

With reference to the third aspect of the present invention, in any one of the above possible implementation manners, in a fourth possible implementation manner, the reservation unit is specifically configured to use Reserving REs in REs that transmit DM-RSs; and/or when sending downlink reference signals to the UE and at least one other UE that occupies a different part of the system bandwidth, the subbands contained in the other at least one UE REs are reserved among the REs used to transmit downlink data.

In conjunction with the third aspect of the present invention, in any one of the above possible implementation manners, in a fifth possible implementation manner, the reservation unit is specifically configured to perform the puncturing or rate matching in the other at least REs are reserved among the REs included in the subband of a UE for transmitting downlink data.

With reference to the third aspect of the present invention, in any one of the above possible implementation manners, in a sixth possible implementation manner, the reservation unit is specifically used for each physical The number of REs reserved among the REs used to transmit the DM-RS included in the resource block PRB is the same as the number of REs reserved among the REs used to transmit the downlink data included in each PRB in the subband of the other UE.

In combination with the third aspect of the present invention, in any one of the above possible implementation manners, in a seventh possible implementation manner, the reserved unit is specifically configured to, in each pair of REs used to transmit the DM-RS, At least one pair of REs is reserved, where each pair of REs refers to two REs that occupy the same frequency domain and are adjacent in the time domain.

With reference to the third aspect of the present invention, in any one of the above possible implementation manners, in an eighth possible implementation manner, the transmission unit is specifically configured to periodically transmit on the reserved RE, or The reserved REs and the REs used to transmit downlink data are configured to transmit CSI-RS.

With reference to the third aspect of the present invention, in any one of the above possible implementation manners, in a ninth possible implementation manner, the indication message sent by the transmission unit is also used to indicate that the UE receives the indication message In at least one subsequent subframe, the CSI-RS and/or the transmitted DM-RS are obtained on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

According to the fourth aspect of the present invention, a device for transmitting downlink signals is provided, including: a resource obtaining unit, configured to obtain REs reserved by the network side in resource elements RE used for transmitting downlink demodulation reference signals DM-RS, and transmit the obtained reserved REs to the signal obtaining unit; the signal obtaining unit is configured to use the reserved REs transmitted by the resource obtaining unit on the reserved REs, or on the reserved REs and use The channel state information reference signal CSI-RS is obtained on the RE transmitting the downlink data.

With reference to the fourth aspect of the present invention, in a first possible implementation manner, the signal obtaining unit is further configured to obtain the DM-RS and /or CSI-RS.

In conjunction with the fourth aspect of the present invention, the first possible implementation manner, in the second possible implementation manner, further includes: a receiving unit, configured to receive the CSI-RS and/or transmission instruction from the network side Or transmit an indication message of the RE information of the DM-RS; the resource obtaining unit is specifically configured to obtain the RE reserved by the network side among the REs used to transmit the DM-RS according to the received indication message The signal obtaining unit is specifically configured to obtain a CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data according to the received indication message And/or obtain the DM-RS.

With reference to the fourth aspect of the present invention, in a third possible implementation manner, the signal obtaining unit is specifically configured to obtain the CSI-RS on some or all of the reserved REs, or obtain the CSI-RS on the reserved REs and Selecting a preset number of REs on the REs used to transmit downlink data, and obtaining CSI-RS sent from the network side on the selected preset number of REs, the preset number is less than or equal to the number of reserved REs .

With reference to the fourth aspect of the present invention, and any one of the above possible implementation manners, in a fourth possible implementation manner, the signal obtaining unit is specifically configured to periodically operate on the reserved RE, or on the The CSI-RS is obtained on the reserved RE and the RE used for transmitting downlink data.

In combination with the fourth aspect of the present invention, the above-mentioned second possible implementation manner, in a fifth possible implementation manner, the signal obtaining unit is specifically configured to, in at least one subframe after receiving the indication message, Obtain a CSI-RS and/or obtain a DM-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data according to the received indication message.

According to the fifth aspect of the present invention, a device for transmitting downlink signals is provided, including: a signal processor, configured to reserve REs in resource elements RE used for transmitting downlink demodulation reference signals DM-RS, and use the reserved The RE is transmitted to the transceiver; the transceiver is used to, according to the reserved RE transmitted by the signal processor, on the reserved RE, or on the reserved RE and the RE for transmitting downlink data The upper transmission channel state information reference signal CSI-RS.

With reference to the fifth aspect of the present invention, in a first possible implementation manner, the transceiver is further configured to transmit DM-RS and /or CSI-RS.

With reference to the fifth aspect of the present invention, in a second possible implementation manner, the transceiver is specifically configured to transmit the CSI-RS on some or all of the reserved REs, or transmit the CSI-RS on the reserved REs and A preset number of REs are selected from the REs used to transmit downlink data, and the CSI-RS sent to the UE is transmitted on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

With reference to the fifth aspect of the present invention, in a third possible implementation manner, the signal processor is specifically configured to reserve REs among REs used to transmit DM-RSs included in the subband configured for the UE and/or when sending a downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data contained in the subbands of the other at least one UE .

According to the sixth aspect of the present invention, there is provided a terminal device, a signal processor, which is used to obtain the RE reserved by the network side in the resource element RE used to transmit the downlink demodulation reference signal DM-RS, and use the obtained reserved RE The REs are transmitted to the transceiver; the transceiver is used for transmitting downlink data on the reserved REs according to the reserved REs transmitted by the signal processor, or on the reserved REs and on the reserved REs The channel state information reference signal CSI-RS is obtained on the RE.

Using the above technical solution, by reserving some REs in the REs used to transmit DM-RS, and then CSI-RS on the reserved REs, or on the reserved REs and the REs used to transmit downlink data , which can better solve the problem of increasing CSI-RS resources under the condition that a large number of LPNs are densely deployed in a certain area without degrading system performance.

Description of drawings

FIG. 1 is a schematic diagram of CSI-RS mapping of a proposed normal CP in the prior art;

Figure 2a is a schematic diagram of centralized deployment of multiple LPNs in one area;

FIG. 2b is a schematic diagram of DMRS mapping under a downlink normal CP;

FIG. 3 is a flowchart of a method for transmitting downlink signals proposed in Embodiment 1 of the present invention;

Figure 4a is a schematic diagram of the pattern information of the downlink DM-RS transmitted in port7 and port8 of the normal CP in the FDD system;

FIG. 4b is a schematic diagram of pattern information of 4 REs reserved in REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 4c is a schematic diagram of pattern information of four REs reserved in REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 4d is a schematic diagram of pattern information of four REs reserved in the REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 4e is a schematic diagram of pattern information of 8 REs reserved in REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 4f is a schematic diagram of pattern information of 8 REs reserved in REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 4g is a schematic diagram of pattern information of 8 REs reserved in REs for transmitting downlink DM-RS proposed in Embodiment 1 of the present invention;

FIG. 5a is a schematic diagram of a proposed system bandwidth allocated to 3 UEs in Embodiment 1 of the present invention;

Fig. 5b is a schematic diagram of the pattern information of the downlink DM-RS and the corresponding sub-band CSI-RS pattern information of the proposed first bandwidth of 4 PRB in Embodiment 1 of the present invention;

Fig. 5c is a schematic diagram of the pattern information of the downlink DM-RS and the corresponding sub-band CSI-RS pattern information of the proposed second bandwidth of 4 PRB in Embodiment 1 of the present invention;

FIG. 5d is a schematic diagram of the pattern information of the proposed downlink DM-RS with a bandwidth of 2 PRB and the corresponding subband CSI-RS pattern information in Embodiment 1 of the present invention;

FIG. 6a is a schematic diagram of UE multiplexing mode in the frequency division multiplexing system proposed in Embodiment 1 of the present invention;

FIG. 6b is a schematic diagram of UE multiplexing mode in the time division multiplexing system proposed in Embodiment 1 of the present invention;

Fig. 7a is a schematic diagram of the structural composition of the proposed device for transmitting downlink signals in Embodiment 1 of the present invention;

FIG. 7b is a schematic diagram of the structural composition of the proposed device for transmitting downlink signals in Embodiment 1 of the present invention;

Fig. 8a is a schematic diagram of the structural composition of the proposed device for transmitting downlink signals in Embodiment 2 of the present invention;

FIG. 8b is a schematic diagram of the structure and composition of the proposed terminal device in Embodiment 2 of the present invention;

FIG. 9 is a flowchart of a method for transmitting downlink signals proposed in Embodiment 3 of the present invention.

detailed description

Aiming at the problem existing in the prior art that when using CSI-RS to implement CSI, for UEs complying with Rel-11 and protocol versions before Rel-11, the performance of the UE will be affected, and in the scenario of dense LPN deployment, according to the existing According to the provisions of the protocol, the resources for transmitting CSI-RS are not enough. In the technical solution proposed here in the embodiment of the present invention, by reserving Some REs, and then CSI-RS on the reserved REs, or on the reserved REs and the REs used to transmit downlink data, can better solve the problem of dense deployment of a large number of LPNs in a certain area. On the premise of not degrading the system performance, the resource of CSI-RS is increased.

In the technical solutions proposed here in the embodiments of the present invention, the so-called resources refer to all REs included in the subband or the entire system bandwidth, and these REs may be configured as REs for transmitting CSI-RS. The multiple REs included in each PRB occupy several REs in each PRB according to a certain time-frequency pattern, and then transmit specific reference signal sequences on the occupied REs to form a CSI-RS. That is to say, each CSI-RS includes multiple REs, RE patterns and reference signal sequences transmitted on the REs. The CSI-RS resources refer to the number of CSI-RSs that can be used for transmission on a subband or within the entire system bandwidth, or the number of REs that can be used to configure CSI-RSs.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The technology described in this article can be used in various communication systems, such as current 2G, 3G communication systems and next-generation communication systems, such as Global System for Mobile Communications (GSM, Global System for Mobile communications), Code Division Multiple Access (CDMA, Code Division Multiple Access) system, Time Division Multiple Access (TDMA, Time Division Multiple Access) system, Wideband Code Division Multiple Access (WCDMA, Wideband Code Division Multiple Access Wireless), Frequency Division Multiple Access (FDMA, Frequency Division Multiple Addressing) system, Orthogonal Frequency Division Multiple Access Orthogonal Frequency-Division Multiple Access (OFDMA, Orthogonal Frequency-Division Multiple Access) system, Single Carrier FDMA (SC-FDMA) system, General Packet Radio Service (GPRS, General Packet Radio Service) system, Long Term Evolution (LTE, Long Term Evolution) system, and others such communication systems.

Various aspects are described herein in connection with terminal devices and/or base stations and/or base station controllers.

The terminal device may be a wireless terminal or a wired terminal. The wireless terminal may be a device that provides voice and/or data connectivity to the user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. The wireless terminal can communicate with one or more core networks via a radio access network (for example, RAN, Radio Access Network), and the wireless terminal can be a mobile terminal, such as a mobile phone (or called a "cellular" phone) and a mobile terminal The computers, which may be, for example, portable, pocket, handheld, built-in or vehicle-mounted mobile devices, exchange speech and/or data with the radio access network. For example, Personal Communication Service (PCS, Personal Communication Service) phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (WLL, Wireless Local Loop) station, Personal Digital Assistant (PDA, Personal Digital Assistant) and other equipment. The wireless terminal can also be called a system, a subscriber unit (Subscriber Unit), a subscriber station (Subscriber Station), a mobile station (Mobile Station), a mobile station (Mobile), a remote station (Remote Station), an access point (AccessPoint), a remote A terminal (Remote Terminal), an access terminal (Access Terminal), a user terminal (UserTerminal), a user agent (User Agent), a terminal device (User Device), or a user equipment (UserEquipment).

A base station (eg, access point) can refer to a device in an access network that communicates with wireless terminals over the air interface through one or more sectors. The base station can be used to convert received over-the-air frames to and from IP packets, acting as a router between the wireless terminal and the rest of the access network, which can include an Internet Protocol (IP) network. The base station may also coordinate attribute management for the air interface. For example, the base station can be a base station (BTS, Base Transceiver Station) in GSM or CDMA, or a base station (NodeB) in WCDMA, or an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in LTE. ), this application is not limited.

The base station controller may be a base station controller (BSC, base station controller) in GSM or CDMA, or a radio network controller (RNC, Radio Network Controller) in WCDMA, which is not limited in this application.

Additionally, the terms "system" and "network" are often used herein interchangeably. The term "and/or" in this article is just an association relationship describing associated objects, which means that there can be three relationships, for example, A and/or B can mean: A exists alone, A and B exist simultaneously, and there exists alone B these three situations. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

In the technical solution proposed by each embodiment of the present invention, as shown in FIG. 2a, a schematic diagram of multiple LPNs being deployed in one area. In FIG. 2a, four LPNs are deployed in one centralized area. The concentrated area generally refers to an area within a preset radius. For example, an area within a radius of 100 meters can be called a concentrated area, such as an indoor office area, an outdoor hotspot area, such as some shopping mall areas included in some areas, and so on. These hotspot areas have the same characteristic that the coverage area is relatively small, such as a coverage radius of 20 meters to 100 meters. Secondly, because the coverage radius is small, the channel is relatively stable, that is, most UEs in the coverage area are walking or stationary. Therefore, from the perspective of the network side, it is equivalent to a short multipath delay of the channel and a high time coherence of the channel. That is to say, the main characteristics of wireless transmission covered by small stations in dense areas are: the channel in this scenario is relatively flat in the frequency domain and relatively stable in time.

Compared with a communication network in which a macro base station is set, it may also be referred to as a macro network or a large network for short. A macro network generally refers to a network with a cell coverage radius of several kilometers to tens of kilometers. In the macro network, the radio frequency pattern of the transmitted downlink DM-RS is shown in Figure 2b. Compared with the deployment scenario of a small cell with a micro station, the transmission of the downlink DM-RS described in Figure 2b is in the frequency domain. The overhead is high. In the technical solution proposed here in the present invention, the technical solution of the present invention is implemented based on two characteristics of small stations in densely populated areas: that is, the channel is flat in the frequency domain and relatively stable in time.

The main realization principles, specific implementation methods and corresponding beneficial effects of the technical solutions of the embodiments of the present invention will be described in detail below with reference to each accompanying drawing.

Embodiment one

As shown in FIG. 3 , Embodiment 1 of the present invention proposes a method for transmitting downlink signals, as shown in FIG. 3 , and its specific processing flow is as follows:

Step 31: Reserve REs among the REs used to transmit downlink DM-RSs.

Wherein, for different UEs, reserving REs in REs used to transmit DM-RSs may include but not limited to include at least one of the following two ways:

The first way: reserve REs in the REs used to transmit DM-RS included in the subband configured for the UE.

The second manner: when sending the downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data included in the subbands of the other at least one UE.

It should be noted that, in the specific implementation of the above two methods, when reserving REs in the REs used to transmit DM-RS, any one of the above two methods can be used alone, or the two methods can be combined use.

In the specific implementation of the above-mentioned second method, the number of REs reserved in the REs used to transmit DM-RS contained in each PRB in the subband configured for the UE is different from the number of REs reserved in the subbands of other UEs. The number of REs reserved among the REs used to transmit downlink data included in each PRB in the PRB is the same.

Specifically, when reserving REs in the REs used to transmit DM-RSs, the reservation may be performed according to the following principle: among each pair of REs used to transmit DM-RSs, at least one pair of REs is reserved, and each pair REs refer to two REs that occupy the same frequency domain and are adjacent in the time domain. The principle of reserving REs is only a preferred implementation method proposed by the embodiments of the present invention based on the DM-RS transmission method in the prior art. The RE of the DM-RS transmitted in the prior art is composed of two REs that occupy the same frequency domain and are adjacent in the time domain, and a length of 2 is used on these two adjacent REs. The superimposed orthogonal code (OCC, Orthogonal Cover Code) is used for code division processing. Therefore, when REs are reserved according to the above principles, the original DM-RS can be transmitted to the UE without modification on the remaining REs. It is used for UE to implement demodulation. Similarly, when REs are reserved on the REs used to transmit DMRS, the REs may not be reserved in an adjacent manner. In this manner, the reserved REs (also referred to as the remaining REs) transmit The DM-RS needs to be modified to achieve the purpose of demodulation. In the technical solutions proposed here in various embodiments of the present invention, the above-mentioned principle of reserving adjacent REs is used as a preferred embodiment to describe the technical solutions proposed in the embodiments of the present invention in detail, but it is not limited to use adjacent REs way to reserve RE.

In a specific implementation, the number of reserved REs may be, but not limited to, one-third, one-half, two-thirds, or three-quarters of the total number of DM-RSs used for transmission.

The specific implementation manner of this step 31 will be described in detail below in combination with specific examples. Assuming that the total number of resource units occupied by the DM-RS sent on the downlink subframe is S, then in this step 31, M REs are reserved in the total number S, where S and M are positive integers. Take port7, port 8, port 9, and port10, which transmit downlink DM-RS in the FDD system, as an example to elaborate. Two of these ports are used as a group. For example, the grouping method can be but not limited to port7 and port 8 is a group, port9 and port10 are a group. Or port7 and port10 as a group, port 8 and port9 as a group. Embodiment 1 of the present invention In the technical solution proposed here, as shown in FIG. 4a , a grouping manner in which port7 and port 8 form a group, and port9 and port10 form a group is taken as an example to describe in detail. As shown in Fig. 4a, the DM-RS transmitted in port7 and port 8 of the downlink DMRS of the normal CP under the FDD system is given. Wherein, FIG. 4a shows 12 REs occupied by the transmission of DM-RS, and the rest are REs occupied by the transmitted downlink data. A certain number of REs are reserved among the 12 REs. The number of reserved REs may be, but not limited to, one-third, one-half, two-thirds, or three-quarters of the total number of DM-RSs used for transmission. Among the pairs of REs used to transmit DM-RSs, at least one pair of REs is reserved, where each pair of REs refers to two REs that occupy the same frequency domain and are adjacent in the time domain. In a specific implementation, in the total number of downlink DM-RSs, some REs are reserved, so that the remaining REs are evenly distributed in the entire bandwidth as much as possible. In a preferred implementation manner, in the technical solution proposed here in Embodiment 1 of the present invention, at least one pair of REs is reserved among each pair of REs for transmitting downlink DM-RS, wherein each pair of REs refers to occupying the same frequency domain , and two REs that are adjacent in the time domain are taken as an example to describe in detail.

It should be noted that, for each PRB for transmitting the downlink DM-RS, REs may be reserved in REs for transmitting the downlink DM-RS included in each PRB in the same manner, or may be different. Preferably, in the technical solution proposed here in Embodiment 1 of the present invention, the same reservation method is used as an example to reserve REs in the REs used to transmit downlink DM-RS contained in each PRB to elaborate. . As shown in Figure 4b, Figure 4c, and Figure 4d, the image information after four (total two pairs) of REs are reserved among twelve (total six pairs) of REs used to transmit downlink DM-RS schematic diagram.

In a specific implementation, not only four REs can be reserved, but more REs can also be reserved. For example, as shown in Fig. Schematic diagram of pattern information after 8 REs.

In the above examples given in Figures 4b to 4g, Figure 4a is used as an example to reserve REs, wherein, in Figures 4b to 4d, and in Figures 4e to 4g, the reserved REs The quantities are not the same. In the specific implementation, the more the number of reserved REs, the more the number of newly added REs that can transmit CSI-RS, and the greater the potential impact on DM-RS demodulation, otherwise the reserved The smaller the number of REs, the smaller the potential impact on DM-RS demodulation, but the fewer newly added REs capable of transmitting CSI-RSs. However, when the number of reserved REs is large, the resource allocated to the UE is a plurality of consecutive RBs, which has little impact on the demodulation performance of the DM-RS.

Step 32, transmit the CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

Wherein, after some REs are reserved in the REs used to transmit downlink DM-RS, the CSI-RS can be transmitted on a part of the reserved REs, or on the reserved REs and the REs used to transmit downlink data . The DM-RS and/or the CSI-RS may also be transmitted on REs other than the reserved REs among the REs used for transmitting the DM-RS.

Preferably, an indication message may be sent to the UE, where the indication message is used to indicate the information of the REs that transmit the CSI-RS and/or transmit the DM-RS. The indication message sent to the terminal device may also be used to instruct the UE to use the reserved RE, or the reserved RE and the RE used for transmitting downlink data in at least one subframe after receiving the indication message. Obtain the CSI-RS and/or the transmitted DM-RS.

Wherein, for different UEs, when REs are reserved in REs used to transmit DM-RSs, the specific implementation methods may not be completely the same, as follows:

Reserve REs in the REs used to transmit DM-RSs included in the subband configured for the UE; and/or when sending downlink reference signals to the UE and at least one other UE occupying a different part of the system bandwidth, at least one other REs are reserved among the REs included in the subbands of the UE for transmitting downlink data.

Specifically, REs may be reserved in REs used to transmit downlink data included in the subband of the other at least one UE based on puncturing or rate matching.

Preferably, the number of REs reserved in REs used to transmit DM-RS contained in each physical resource block PRB in the subband configured for the UE is different from the number of REs contained in each PRB contained in the subband of the other UE. The number of reserved REs among the REs used to transmit downlink data is the same.

Preferably, when reserving REs among the REs used to transmit DM-RSs, the REs can be reserved according to the following principle: among each pair of REs used to transmit DM-RSs, at least one pair of REs is reserved, where each The RE refers to two REs that occupy the same frequency domain and are adjacent in the time domain.

Specifically, an example is used below to describe in detail. Assume that the average total number of resource units occupied by DM-RS sent on the downlink subframe on each PRB is S, and M REs are reserved in S, where S and M are positive integers. Then, after M REs are reserved, the ways of transmitting CSI-RS can be but not limited to the following ways:

The first way: the CSI-RS can be transmitted on K REs among the M REs. Wherein, K is a positive integer less than or equal to M.

Assuming that S=12 and M=8, the value of K may be less than or equal to 8.

The second way: if there is no need to add REs for transmitting CSI-RSs, data or other downlink reference signals can be transmitted on the reserved M REs. For example, data may be transmitted on the reserved M REs.

Assuming that S=12 and M=8, the value of K can be 0.

The third manner: transmit the CSI-RS on the reserved REs and the REs used for transmitting downlink data.

Assuming that S=12, M=8, and the value of K is less than or equal to 8, here 6, then in the third method, 2 REs can be obtained in M, and 4 REs can be obtained on the REs transmitting downlink data, A total of K=6 transmission CSI-RSs.

Wherein, the CSI-RS is transmitted on the reserved REs, or on the reserved REs and the REs used to transmit downlink data. In a specific implementation manner, the CSI-RS is transmitted on some or all of the reserved REs. RS, or select a preset number of REs on the reserved REs and REs used to transmit downlink data, and transmit the CSI-RS sent to the UE on the selected preset number of REs, and the preset number is less than or equal to Number of reserved REs.

Since the downlink DM-RS is defined differently for the UE, that is, it is not completely the same for the CSI-RS. Specifically, it can be divided into subband-level CSI-RS or system-level CSI-RS, which will be described in detail below.

For the CSI-RS at the subband level, because the DM-RS is specific to different UEs, specifically because the number of RBs configured for each UE is different, the number of REs occupied by the DM-RS is also not completely the same. For example, in a 20 MHz communication system, there are 100 PRBs in the frequency domain, and it is assumed that the 100 PRBs are fixedly allocated to 3 UEs, namely UE1, UE2, and UE3. As shown in Figure 5a, three UEs are configured with 25PRB, 25PRB, and 50PRB respectively. In Fig. 5a, the resources allocated to each UE in the frequency domain are continuously allocated. In a specific implementation, when configuring resources for the UE, it may be discontinuously configured. For ease of description, the embodiments of the present invention are described here in detail by taking continuous allocation as an example. As shown in Figure 5a, after configuring 50 PRBs for UE3, UE3 can determine that 50 consecutive PRBs out of 100 PRBs are configured for itself, but the UE cannot know the usage of the system bandwidth of. Therefore, for UE3, the resource units occupied by its corresponding CSI-RS are included in the 50 PRBs configured for it. Therefore, the CSI-RS is equivalent to a terminal device-specific CSI-RS, and for the UE3, in the technical solution proposed here in the embodiment of the present invention, the frequency domain resource occupied by the newly added transmission CSI-RS is the same as that of UE3 The PRBs of the allocated data bandwidth are consistent, and there are no newly added CSI-RS REs on PRBs other than those allocated to UE3.

Further, if UE1 and UE2 are UEs complying with standards of old versions (such as Rel-11 and earlier versions), UE1 and UE2 cannot know the newly added CSI-RS in the standard of Rel-12 version. Based on this, in the technical solution proposed here in the embodiment of the present invention, in specific implementation, subband-level CSI-RS can well coexist with UEs that follow the old version of the standard, that is, downlink DM-RS puncturing and newly added The CSI-RS only occurs on the subband of the UE of the Rel-12 version.

The method for configuring the subband CSI-RS is further described below by taking the pattern information shown in FIG. 4b as an example. As shown in Figure 5b, the newly added REs that transmit CSI-RS are on symbols 4 and 5 on even and odd time slots. In Figure 5b, the newly added REs that transmit CSI-RS are in the frequency domain The location is not the same. Assume that on symbols 4 and 5 of even time slots, the port numbers for transmitting CSI-RS are m, m+1, where m is a non-negative integer used to identify a pair of ports for transmitting CSI-RS. On symbols 4 and 5 on odd time slots, port numbers for transmitting CSI-RS are n, n+1, where n is a non-negative integer. According to the technical solutions proposed above in the embodiments of the present invention, it can be known that the added CSI-RS can be transmitted on the reserved REs, or the added CSI-RSs can be transmitted on the reserved REs and the REs used for transmission of downlink data. Comparing Fig. 5b with Fig. 4b, it can be seen that in Fig. 5b, the added CSI-RS is transmitted on the RE used for transmitting downlink data. That is, the newly added RE for transmitting the CSI-RS may be the RE used for transmitting downlink data, and is not limited to the symbol of the RE where the DM-RS before the reserved RE is located. Preferably, the number of symbols on the even and odd time slots may also appear on the same symbol at the same time, or may not appear on the same symbol at the same time.

Preferably, when CSI-RS is transmitted on reserved REs, and/or on reserved REs and REs used for transmitting downlink data, for each PRB, the pattern information on each PRB may be The same or different, as shown in Figure 5c, in the pattern information of the downlink reference signal with a bandwidth of 4 PRB, in PRB1, the CSI- RS, in PRB2, CSI-RS is transmitted on REs of symbol 0 and symbol 1 in even and odd time slots, and in PRB3, CSI is transmitted on REs of symbols 2 and 3 in even and odd time slots - RS, in PRB4, CSI-RS is transmitted on REs of symbols 4 and 5 of even and odd slots.

When CSI-RS is transmitted in REs at the same position in each PRB, that is, when CSI-RS is transmitted in a completely orthogonal manner, the number of REs that can be increased to transmit CSI-RS is equal to the number of reserved REs. CSI-RSs are transmitted in REs at different positions in each PRB, that is, in a non-completely orthogonal manner, the number of REs that can be increased for transmitting CSI-RSs is greater than the number of reserved REs. When the resources for transmitting CSI-RS are limited, the resources for transmitting CSI-RS can be increased by means such as frequency hopping, that is, for multiple configured CSI-RS, REs for transmitting CSI-RS can be transmitted on some PRBs Collision, while REs transmitting CSI-RS on other PRBs do not collide, can better increase the number of available resources for transmitting CSI-RS.

In FIG. 5b , the newly added CSI-RS is transmitted by two adjacent REs through an OCC with a length of 2. In a specific implementation, the CSI-RS may also be transmitted through a separate single RE. Specifically, as shown in FIG. 5d , the bandwidth is 2 PRB as an example to describe in detail. In the pattern information shown in FIG. 5d, there are four CSI-RSs in total, and each CSI-RS occupies only one RE in each PRB, and different CSI-RSs are not adjacent in time. In each PRB, add 2 new REs for transmitting CSI-RS. In even time slots, the newly added REs for transmitting CSI-RS are on the REs of symbol 2 and symbol 5 respectively. In odd time slots, newly add The REs transmitting the CSI-RS are respectively on the REs of symbol 2 and symbol 4. It can be seen from FIG. 5d that symbols 2 and 5 and symbols 2 and 4 are not adjacent.

It can be known from the above that when reserving a certain number of REs among the REs used to transmit DM-RS on the PDSCH channel corresponding to the UE conforming to the Rel-12 version, there can be a variety of different reservation methods. For reserving The subsequent REs can be configured with various pattern information for transmitting the CSI-RS. Moreover, it can be seen from the above discussion that after reserving a certain number of REs for transmitting DM-RSs, when configuring REs for transmitting CSI-RSs, it is possible, but not limited, to configure the transmission of CSI-RSs on the reserved REs. RS REs can also be configured to transmit CSI-RS on reserved REs and REs used to transmit downlink data. The number of configured transmission CSI-RSs can be the same as the number of reserved REs, or it can be different. Similarly, when the numbers are different, the remaining reserved REs can be configured to transmit downlink data.

For CSI-RS at the system bandwidth level, the RE transmitting CSI-RS is set on the entire system bandwidth, not like in the sub-band level CSI-RS, the RE transmitting CSI-RS is set on the bandwidth corresponding to a specific UE superior.

As shown in Table 1 below, in the LTE communication system, the corresponding relationship between the system bandwidth and the number of PRBs.

Table 1

System Bandwidth (MHz) 1.4 3 5 10 15 20 Number of PRBs 6 15 25 50 75 100

As shown in Table 1, the network side can determine the number of PRBs occupied by transmitting CSI-RS according to the actual bandwidth of the system, and REs for transmitting CSI-RS are distributed on PRBs included in the entire system bandwidth. Moreover, in the CSI-RS at the system bandwidth level, reserving REs among REs used to transmit DM-RSs is still performed for each UE. That is, for UEs that meet the channel flat condition, some REs are reserved to achieve the purpose of increasing transmission CSI-RS resources. For example, there are 3 UEs in the system bandwidth, and the channel corresponding to only one UE is flat, so only some REs are reserved on the REs of the downlink DM-RS transmitted on the bandwidth corresponding to the UE. A specific example will be used to describe in detail below.

As shown in Figure 6a, assuming that there are three UEs in the system bandwidth, namely UE1-UE3, and only the channels corresponding to UEs meet the channel platform conditions, then for UE3, on the PRB corresponding to UE3, transmit DM- A certain number of REs are reserved in the REs of the RS. However, for UE1 and UE2, all REs for transmitting DM-RSs are still reserved on the PRBs configured for UE1 and UE2. Since the reserved REs (used to transmit the newly added CSI-RS) are for the entire system bandwidth, that is, a certain number of REs for transmitting CSI-RSs need to be added to the bandwidth occupied by UE1 and UE2. Then it is necessary to reserve the REs for transmitting downlink data of UE1 and UE2 at the positions of REs for transmitting newly added CSI-RSs, and avoid the REs occupied by transmitting DM-RSs, so as to provide the ability to transmit newly added REs. The REs occupied by the CSI-RS. Thus, the demodulation performance of the system is guaranteed.

Preferably, resources may be configured for the UE in a time division multiplexing manner or a frequency division multiplexing manner. As shown in Figure 6b, when time division multiplexing is used to configure resources for the UE, subframes 0, 1, 8, and 9 are allocated to some of the REs reserved for transmitting downlink DM-RS, and according to the reserved The reserved REs are configured for use by UEs that transmit CSI-RS REs, that is, UE3 in FIG. 6a , and other subframes 2-7 can be configured for use by other UE1-UE2. Using time division multiplexing to allocate resources to two different UEs can better avoid performance impact on UEs that do not reserve part of REs in the REs used to transmit downlink DM-RSs.

In the technical solutions proposed in steps 31 to 32 above, it is possible, but not limited to, to periodically configure and transmit CSI-RS on reserved REs, or on reserved REs and REs used for transmission of downlink data , can also be performed aperiodically. For aperiodic execution, for example, when the UE receives a high-level or physical layer dynamic signaling indication, such as when receiving a physical layer downlink control information (DCI, Downlink Control Informaiton) signaling, the UE can It is expected to obtain the CSI-RS at a specific position, such as receiving the CSI-RS signal in the current subframe indicated by the signaling, or receiving the CSI-RS signal in multiple subframes after receiving the signaling indication, Otherwise these signals cannot be expected to be received. Periodically, that is, configure a certain sending cycle for the UE, such as 5ms interval, and the start time of receiving the first one. When the UE receives these signalings, the UE will receive them at the corresponding position every 5ms. to the CSI-RS signal. The periodic CSI-RS is shown in Table 2 below: the signaling I _CSI-RS is used to indicate the periodic information T _{CSI-RS that appears in the CSI-RS} and the location information Δ _CSI-RS that appears in the first subframe.

Table 2

In the above steps 31 to 32, the network side configures and transmits CSI-RS on the reserved REs, or on the reserved REs and the REs used to transmit downlink data, and can inform the terminal side, or through It is agreed that the terminal side obtains the corresponding information. Specifically, when the network side notifies the terminal side of relevant information, it may send a notification message to the UE. The notification message may be sent before step 31, or after step 32, or during the execution of step 31 and step 32. It only needs to inform the UE of relevant configuration information.

Specifically, it can be seen from the above discussion that there may be multiple different methods of reserving REs for DM-RS transmission on the PDSCH channel corresponding to the UE conforming to the Rel-12 version, and multiple REs may be configured for the reserved REs. Pattern information of REs that transmit different CSI-RSs. Moreover, when the newly added REs for transmitting CSI-RS are configured, they are not completely configured on the reserved REs, but may also be configured on the REs used for transmitting downlink data. The configured number of REs for transmitting the CSI-RS is less than or equal to the number of reserved REs. When it is less than the number of reserved REs, the redundant reserved REs may be used to transmit downlink data on the DL-SCH channel. Regardless of the above methods, after the configuration is completed, the network side needs to let the terminal side know the relevant configuration information. The network side and the terminal side may notify the terminal side of relevant configuration information according to a pre-agreement, that is, not occupying transmission resources, or notify the terminal side of relevant configuration information by sending notification messages or indication information. Specifically, the terminal side needs to know the following information:

After REs are reserved in the REs used to transmit DM-RSs, when the REs used to transmit CSI-RSs are not added, the information that the terminal side needs to know is: the pattern of REs reserved in the REs used to transmit DM-RSs , and the number of reserved REs. Preferably, the information can be notified to the terminal side through signaling.

After REs are reserved in the REs used to transmit DM-RSs, when adding REs used to transmit CSI-RSs, the information that the terminal side needs to know is: the pattern of REs is reserved in the REs used to transmit DM-RSs, and the number of reserved REs, how many of the reserved REs are used to configure the REs for transmitting CSI-RS, and how many of the reserved REs are used to configure the transmission of downlink data on the DL-SCH channel, and Including the number of ports for transmitting the increased CSI-RS, time-frequency pattern information, and the like. Preferably, the information can be notified to the terminal side through signaling.

Wherein, the CSI-RS may be non-zero power or zero power. For zero-power CSI-RS, no information is sent when the RE of the CSI-RS is configured, and no reference signal is sent, that is, it is "empty". From the perspective of transmission power, the transmission power on these REs is zero. For CSI-RS with non-zero power, a specific reference signal is sent on the RE configured with CSI-RS, so that the UE can perform measurement and estimation according to the corresponding CSI-RS.

It should be noted that the added CSI-RS for transmission may be configured for use by one UE, and may also be configured for use by multiple different UEs. Among the REs used to transmit DM-RSs, the REs on the DM-RS after the REs are reserved can be allocated to the same user as the newly added CSI-RS, and can also be configured to be used by different users. How to configure is arranged by the network according to scheduling requirements. For different UEs, they only receive reference signals on corresponding time-frequency resources according to the instruction signaling sent by the network.

In the technical solution proposed above in Embodiment 1 of this mode, in specific implementation, the network side can feed back the UE after measuring the existing reference signal (CRS (cell-specific reference signal) or CSI-RS) If the CSI fed back by a certain UE indicates that the UE is in a flat channel condition in the frequency domain, REs can be reserved for the UE on the REs used to transmit DM-RS and The configuration parameters of the DM-RS of reserved REs may be indicated to the UE through signaling. A method for judging whether the channel is flat in the frequency domain is to check whether the CQI (Channel Quality Indicator) on each sub-band fed back in the CSI information is the same or not. If it is necessary to configure REs for CSI-RS transmission for the UE, add REs for CSI-RS transmissions according to the reserved REs, configure the newly added CSI-RSs for the UE first, and inform the UE of the CSI-RS configuration information . The network side sends the corresponding DM-RS and CSI-RS according to the pattern information of the REs that transmit the DM-RS and the REs that transmit the CSI-RS configured for the UE, and then configure the corresponding downlink data on the remaining REs transmission.

In the technical solution proposed above in the first embodiment of the present invention, the normal CP under FDD is mainly used as an example to elaborate in detail. In specific implementation, it can also be extended to extend the CP. The difference between the normal CP and the extended CP is that there are 7 OFDM symbols in each slot of the normal CP, and 6 OFDM symbols in each slot of the extended CP, so the positions of the pilot patterns of the DM-RS and CSI-RS are slightly different. There are differences, but the other parts are the same. The structure of some special subframes in the TDD system is slightly different from that in the FDD system, which will cause the positions of the pilot patterns of the DM-RS and CSI-RS to be slightly different, and the other parts are the same. Therefore, the technical solution proposed above in Embodiment 1 of the present invention is also applicable to the frame structures of FDD and TDD, and is also applicable to the CP types of normal CP and extended CP.

Embodiment 1 of the present invention In the technical solution proposed above, by reserving some REs in the REs used to transmit the downlink DM-RS, the REs used to transmit the newly added CSI-RS are configured according to the reserved REs, on the one hand The demodulation performance of the downlink UE on the DM-RS is not affected, and at the same time, the available number of CSI-RS resources is increased by using newly increased CSI-RS resources. Therefore, the problem of degradation of demodulation performance caused by the use of original CSI-RS resources in the prior art is further reduced.

Correspondingly, Embodiment 1 of the present invention also proposes a device for transmitting downlink signals. The device is located on the network side, as shown in FIG. 7a, including:

The reserving unit 701 is configured to reserve REs in REs used for transmitting downlink demodulation reference signals DM-RS, and transmit the reserved REs to the transmitting unit 702 .

Specifically, the above-mentioned reserving unit 701 is specifically configured to reserve REs in the REs used to transmit DM-RSs contained in the subband configured for the UE; When some other at least one UE sends the downlink reference signal, REs are reserved in the REs used for transmitting downlink data included in the subband of the other at least one UE.

Specifically, the above-mentioned reserving unit 701 is specifically configured to reserve REs in REs used for transmitting downlink data included in the subband of the other at least one UE based on puncturing or rate matching.

Specifically, the above-mentioned reservation unit 701 is specifically configured to use the number of REs reserved in REs used to transmit DM-RSs included in each physical resource block PRB in the subband configured for the UE to be different from the number of REs reserved in the other The number of REs reserved among REs used to transmit downlink data contained in each PRB in the subband of the UE is the same.

Specifically, the above reservation unit 701 is specifically configured to reserve at least one pair of REs among the pairs of REs used to transmit DM-RSs, where each pair of REs refers to occupying the same frequency domain and being adjacent in the time domain The two RE.

The transmission unit 702 is configured to transmit the channel state information reference on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data according to the reserved REs transmitted by the reservation unit 701 Signal CSI-RS.

Specifically, the transmission unit 702 is further configured to transmit DM-RSs and/or CSI-RSs on REs other than reserved REs among the REs used to transmit DM-RSs.

Specifically, the transmission unit 702 is further configured to send an indication message to the UE, where the indication message is used to indicate the information of the RE that transmits the CSI-RS and/or transmits the DM-RS.

Specifically, the above-mentioned transmission unit 702 is specifically configured to transmit CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and the REs used to transmit downlink data, The CSI-RS sent to the UE is transmitted on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

Specifically, the transmission unit 702 is specifically configured to periodically configure and transmit CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

Specifically, the indication message sent by the above-mentioned transmission unit 702 is also used to instruct the UE to, in at least one subframe after receiving the indication message, on the reserved RE or on the reserved RE The CSI-RS and/or the transmitted DM-RS are obtained on the RE and the RE used for transmitting downlink data.

Correspondingly, Embodiment 1 of the present invention also proposes a device for transmitting downlink signals, which is located on the network side, as shown in Figure 7b, including:

The signal processor 801 is configured to reserve REs in resource elements RE used for transmitting downlink demodulation reference signals DM-RS, and transmit the reserved REs to the transceiver 802 .

Specifically, the above-mentioned signal processor 801 is specifically configured to reserve REs in the REs used to transmit DM-RSs included in the subband configured for the UE; When some other at least one UE sends the downlink reference signal, REs are reserved in the REs used for transmitting downlink data included in the subband of the other at least one UE.

Specifically, the above-mentioned signal processor 801 is specifically configured to reserve REs in REs used for transmitting downlink data included in the subband of the other at least one UE based on puncturing or rate matching.

Specifically, the above-mentioned signal processor 801 is specifically configured to use the number of REs reserved in REs used to transmit DM-RS contained in each physical resource block PRB in the subband configured for the UE to be different from the number of REs reserved in the other The number of REs reserved among REs used to transmit downlink data contained in each PRB in the subband of the UE is the same.

Specifically, the above-mentioned signal processor 801 is specifically configured to reserve at least one pair of REs among the pairs of REs used to transmit DM-RSs, where each pair of REs refers to occupying the same frequency domain and being adjacent in the time domain The two RE.

The transceiver 802 is configured to transmit channel state information on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data according to the reserved REs transmitted by the signal processor 801 Reference signal CSI-RS.

Specifically, the transceiver 802 is further configured to transmit DM-RSs and/or CSI-RSs on REs other than reserved REs among the REs used to transmit DM-RSs.

Specifically, the above-mentioned transceiver 802 is further configured to send an indication message to the UE, where the indication message is used to indicate the information of the RE that transmits the CSI-RS and/or transmits the DM-RS.

Specifically, the above-mentioned transceiver 802 is specifically configured to transmit CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and the REs used to transmit downlink data , transmitting the CSI-RS sent to the UE on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

Specifically, the transceiver 802 is specifically configured to periodically configure and transmit CSI-RSs on the reserved REs, or on the reserved REs and the REs used to transmit downlink data.

Specifically, the indication message sent by the above-mentioned transceiver 802 is also used to instruct the UE to, in at least one subframe after receiving the indication message, use the reserved RE or the reserved RE The CSI-RS and/or the transmitted DMRS are obtained on the above REs and on the REs used for transmitting downlink data.

Embodiment 1 of the present invention In the technical solution proposed above, by reserving REs on the REs used to transmit downlink DN-RS, and then on the reserved REs, or on the reserved REs The CSI-RS on the data RE can better solve the problem of increasing the resources of the CSI-RS without degrading the system performance under the condition that a large number of LPNs are densely deployed in a certain area.

Embodiment two

Correspondingly, Embodiment 2 of the present invention here proposes a method for transmitting downlink signals, which is applied on the terminal side, and its specific processing flow is as follows:

Step 1: The terminal device obtains REs reserved by the network side among REs used for transmitting downlink DM-RSs.

Wherein, for different UEs, the network side may, but is not limited to, include at least one of the following two methods in reserving REs in the REs used to transmit DM-RSs:

The first way: reserve REs in the REs used to transmit DM-RS included in the subband configured for the UE.

The second manner: when sending the downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data included in the subbands of the other at least one UE.

In the subband configured for the UE, the number of REs reserved for the transmission of DM-RS contained in each physical resource block PRB is different from the number of reserved REs contained in each PRB used for transmission of downlink in the subbands of other UEs. The number of REs reserved in REs of data is the same. Specifically, when reserving REs in the REs used to transmit DM-RSs, the reservation may be performed according to the following principle: among each pair of REs used to transmit DM-RSs, at least one pair of REs is reserved, and each pair REs refer to two REs that occupy the same frequency domain and are adjacent in the time domain. In a specific implementation, the number of reserved REs may be, but not limited to, one-third, one-half, two-thirds, or three-quarters of the total number of DM-RSs used for transmission.

Specifically, for the specific implementation manner of the RE reserved by the network side among the REs used to transmit the downlink DM-RS, please refer to the detailed description in step 31 in the first embodiment above, and the second embodiment of the present invention will not be repeated here.

Step 2: Obtain the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data.

Preferably, the terminal device can also obtain the DM-RS and/or the CSI-RS on REs other than the reserved REs among the REs used to transmit the DM-RS.

Wherein, the terminal device obtains the DM-RS and/or the CSI-RS on the REs except the reserved REs among the REs used for transmitting the DM-RS. The terminal device can also obtain CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and REs used to transmit downlink data, and select a preset number of REs The CSI-RS sent from the network side is obtained on the REs, and the preset number is less than or equal to the number of reserved REs.

Wherein, the terminal device may periodically or aperiodically obtain the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data. For example, the CSI-RS may be obtained periodically on reserved REs, or on reserved REs and REs used for transmitting downlink data.

If the CSI-RS is obtained aperiodically on the reserved RE, or on the reserved RE and the RE used to transmit downlink data, it can be done according to the instruction message sent by the network side .

Preferably, the above method may also include:

Before the terminal device obtains the REs reserved by the network side among the REs used to transmit the DM-RS, it also includes: the terminal device receives information from the network side indicating the REs used to transmit the CSI-RS and/or transmit the DM-RS instruction message. According to the received indication message, the terminal device obtains REs reserved by the network side among the REs used for transmitting the DM-RS.

Further, the terminal device may obtain the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data according to the received indication message, and/or obtain DM-RS.

Preferably, in at least one subframe after receiving the indication message, the terminal device, according to the received indication message, on the reserved RE, or on the reserved RE and the Obtain the CSI-RS and/or obtain the DM-RS on the RE. Specifically, for the specific implementation manner of obtaining the CSI-RS on the reserved REs, or on the reserved REs and the REs used to transmit downlink data, please refer to the detailed description in step 32 in the first embodiment above. The second embodiment of the invention will not be repeated here.

Correspondingly, Embodiment 2 of the present invention here also proposes a device for transmitting downlink signals. The device may be located at the terminal side, as shown in FIG. 8a , including:

The resource obtaining unit 81 is configured to obtain the RE reserved by the network side in the resource element RE used for transmitting the downlink demodulation reference signal DM-RS, and transmit the obtained reserved RE to the signal obtaining unit 82 .

A signal obtaining unit 82, configured to obtain channel state information on the reserved REs, or on the reserved REs and the REs used to transmit downlink data according to the reserved REs transmitted by the resource obtaining unit 81 Reference signal CSI-RS.

Specifically, the above-mentioned signal obtaining unit 82 is specifically configured to obtain CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and the REs used to transmit downlink data Obtain the CSI-RS sent from the network side on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

Specifically, the above-mentioned signal obtaining unit 82 is specifically configured to periodically obtain the CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

Specifically, the signal obtaining unit 82 is further configured to obtain DM-RSs and/or CSI-RSs on REs other than the reserved REs among REs used for transmitting DM-RSs.

Specifically, the above-mentioned signal obtaining unit 82 is specifically configured to, in at least one subframe after receiving the indication message, on the reserved RE or on the reserved RE according to the received indication message Obtain the CSI-RS and/or obtain the DM-RS on the RE and the RE used for transmitting downlink data.

Preferably, the above-mentioned device may also include:

The receiving unit is configured to receive an indication message from the network side for indicating the information of REs that transmit the CSI-RS and/or transmit the DM-RS.

The above-mentioned resource obtaining unit 81 is specifically configured to obtain REs reserved by the network side among the REs used to transmit DM-RSs according to the received indication message;

The above-mentioned signal obtaining unit 82 is specifically configured to obtain the CSI-RS and /or obtain the DM-RS.

Correspondingly, the embodiment of the present invention also proposes a terminal device here, as shown in FIG. 8b, including:

The signal processor 901 is configured to obtain the RE reserved by the network side in the resource element RE used for transmitting the downlink demodulation reference signal DM-RS, and transmit the obtained reserved RE to the transceiver 902 .

The transceiver 902 is configured to obtain channel state information on the reserved REs, or on the reserved REs and the REs used to transmit downlink data according to the reserved REs transmitted by the signal processor 901 Reference signal CSI-RS.

Specifically, the above-mentioned transceiver 902 is specifically configured to obtain CSI-RS on some or all of the reserved REs, or select a preset number of REs on the reserved REs and the REs used to transmit downlink data Obtain the CSI-RS sent from the network side on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs.

Specifically, the above-mentioned transceiver 902 is specifically configured to periodically obtain a CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data.

Specifically, the transceiver 902 is further configured to obtain DM-RSs and/or CSI-RSs on REs other than the reserved REs among the REs used for transmitting DM-RSs.

Specifically, the above-mentioned transceiver 902 is specifically configured to, in at least one subframe after receiving the indication message, operate on the reserved RE or on the reserved RE according to the received indication message in at least one subframe. Obtain the CSI-RS and/or obtain the DM-RS on the RE and the RE used for transmitting downlink data.

Preferably, the above-mentioned transceiver 902 is further configured to receive an indication message from the network side for indicating the information of the REs that transmit the CSI-RS and/or transmit the DM-RS.

The above-mentioned signal processor 901 is specifically configured to obtain, according to the received indication message, REs reserved by the network side among REs used for transmitting DM-RSs.

The above-mentioned transceiver 902 is specifically configured to obtain the CSI-RS and /or obtain the DM-RS.

Embodiment Three

In Embodiment 1 and Embodiment 2 above, the downlink signal transmission method proposed here in the present invention can be executed on the network side or on the terminal side. If it is executed on the network side or on the terminal side alone, only the The technical solutions proposed in Embodiment 1 and Embodiment 2 of the present invention can be realized by agreement. Of course, the network side can also inform the terminal side of the relevant reserved information and configuration information, and the terminal side can perform corresponding processing according to the relevant information notified by the network side. Based on this, Embodiment 3 of the present invention proposes a method for transmitting downlink signals, as shown in FIG. 9 , and its specific processing flow is as follows:

Step 91 , the network side reserves REs among the REs used to transmit the downlink DM-RS.

For the specific implementation manner of the network side device reserving REs among the REs used to transmit downlink DMRS, please refer to the detailed description in step 31 in the first embodiment above, and the technical solution proposed here in the third embodiment of the present invention will not be repeated here.

Step 92 , the network side device transmits the CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

Wherein, after some REs are reserved in the REs used to transmit downlink DM-RS, the CSI-RS can be transmitted on a part of the reserved REs, or on the reserved REs and the REs used to transmit downlink data . The DM-RS and/or the CSI-RS may also be transmitted on REs other than the reserved REs among the REs used for transmitting the DM-RS. Please refer to the detailed explanation in step 32 in the first embodiment above for the specific implementation manner, and the technical solution proposed here in the third embodiment of the present invention will not be repeated here.

Step 93, the network side device sends an indication message to the UE.

Wherein, the indication message is used to indicate the information of the REs that transmit the CSI-RS and/or transmit the DM-RS. The UE is informed on which REs to obtain the transmitted CSI-RS and/or the transmitted DM-RS.

In step 94, the UE obtains the reserved REs from the REs used to transmit the downlink DM-RS according to the received indication message.

Step 95 , the UE transmits the CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

It should be noted that, in the technical solution proposed here in Embodiment 3 of the present invention, the network side can periodically configure and transmit CSI- RS, after the configuration is completed, the UE can be notified through an indication message, and the subsequent UE can periodically obtain the CSI-RS configured by the network side on the reserved RE, or on the reserved RE and the RE used to transmit downlink data Wait for the downlink reference signal.

When the resources for transmitting CSUI-RS are sufficient, the network side can perform step 91 and step 92 aperiodically, and at this time, it can send indication information to the UE before or after the execution, and the UE at least In a subframe, the CSI-RS and/or the transmitted DMRS are obtained on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data.

In the third embodiment of the present invention, in the technical solution proposed here, by reserving some REs on the REs used to transmit the downlink DM-RS, the REs used to transmit the CSI-RS can be increased. On the one hand, it does not affect the downlink UE on the DM-RS. demodulation performance, and by using newly increased CSI-RS resources, the available number of CSI-RS resources is increased. When the CSI-RS resources are not tight, the use of CSI-RS resources defined by existing protocols can be reduced, thereby further reducing the degradation of demodulation performance caused by using the original CSI-RS resources in the prior art question.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, devices (devices), or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (devices) and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (37)

1. A method for transmitting downlink signals, comprising: Reserve REs in the resource elements RE used for transmitting the downlink demodulation reference signal DM-RS; The channel state information reference signal CSI-RS is transmitted on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data. 2. The method of claim 1, further comprising: The DM-RS and/or the CSI-RS are transmitted on REs other than the reserved REs among the REs used for transmitting the DM-RS. 3. The method according to claim 1 or 2, further comprising: Sending an indication message to the UE, where the indication message is used to indicate information about REs that transmit the CSI-RS and/or transmit the DM-RS. 4. The method according to claim 1, wherein transmitting the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data, comprises: transmit CSI-RS on some or all of the reserved REs, or Selecting a preset number of REs on the reserved REs and the REs used to transmit downlink data, and transmitting the CSI-RS sent to the UE on the selected preset number of REs, the preset number is less than or It is equal to the number of reserved REs. 5. The method according to claim 1, wherein reserving REs in REs used to transmit DM-RSs comprises: Reserving REs in the REs used to transmit DM-RSs included in the subband configured for the UE; and/or When sending the downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data included in the subband of the other at least one UE. 6. The method according to claim 5, wherein reserving REs in the REs used to transmit downlink data contained in the subband of the other at least one UE comprises: Reserve REs in the REs used to transmit downlink data contained in the subband of the other at least one UE based on puncturing or rate matching. 7. The method according to claim 5, wherein the number of REs reserved in REs used to transmit DM-RSs included in each physical resource block (PRB) in the subband configured for the UE is the same as that in The number of reserved REs contained in each PRB in the subbands of the other UEs used to transmit downlink data is the same. 8. The method according to any one of claims 1-2 or 4-7, wherein reserving REs in REs used to transmit DM-RSs includes: Among the pairs of REs used to transmit DM-RSs, at least one pair of REs is reserved, where each pair of REs refers to two REs that occupy the same frequency domain and are adjacent in the time domain. 9. The method according to any one of claims 1-2 or 4-7, characterized in that, on the reserved REs, or on the reserved REs and the REs used to transmit downlink data Transmission of CSI-RS, including: Periodically configure and transmit CSI-RS on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data. 10. The method according to claim 3, wherein the indication message is further used to instruct the UE to, in at least one subframe after receiving the indication message, on the reserved RE, Or obtain the CSI-RS and/or the transmitted DM-RS on the reserved RE and the RE used for transmitting downlink data. 11. A method for transmitting downlink signals, comprising: The terminal device obtains the RE reserved by the network side in the resource element RE used for transmitting the downlink demodulation reference signal DM-RS; A channel state information reference signal CSI-RS is obtained on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data. 12. The method of claim 11, further comprising: The terminal device obtains the DM-RS and/or the CSI-RS on the REs except the reserved REs among the REs used for transmitting the DM-RS. 13. The method according to claim 11 or 12, wherein before the terminal device obtains the REs reserved by the network side among the REs used to transmit the DM-RS, further comprising: The terminal device receives an indication message from the network side for indicating information on REs that transmit the CSI-RS and/or transmit the DM-RS; The terminal device obtains the REs reserved by the network side in the REs used to transmit the DM-RS, including: The terminal device obtains the RE reserved by the network side among the REs used to transmit the DM-RS according to the received indication message; Obtaining the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data, includes: The terminal device obtains the CSI-RS and/or obtains the DM- RS. 14. The method according to claim 11, wherein obtaining the CSI-RS on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data comprises: Obtain a CSI-RS on some or all of the REs reserved, or Select a preset number of REs on the reserved REs and the REs used to transmit downlink data, and obtain the CSI-RS sent from the network side on the selected preset number of REs, and the preset number is less than Or equal to the number of reserved REs. 15. The method according to any one of claims 11-12 or 14, characterized in that the CSI is transmitted on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data -RS, including: The CSI-RS is periodically obtained on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data. 16. The method according to claim 13, wherein the terminal device transmits downlink data on the reserved RE or on the reserved RE according to the received indication message Earn CSI-RS on REs, including: In at least one subframe after receiving the indication message, according to the received indication message, on the reserved RE, or on the reserved RE and the RE used for transmitting downlink data Get a CSI-RS and/or get a DM-RS. 17. A device for transmitting downlink signals, comprising: The reservation unit is used to reserve REs in the resource units RE used to transmit the downlink demodulation reference signal DM-RS, and transmit the reserved REs to the transmission unit; The transmission unit is configured to transmit the channel state information reference signal CSI on the reserved REs according to the reserved REs transmitted by the reservation unit, or on the reserved REs and the REs used for transmitting downlink data -RS. 18. The apparatus according to claim 17, wherein the transmission unit is further configured to transmit DM-RS and/or CSI on REs other than reserved REs among the REs used to transmit DM-RS -RS. 19. The apparatus according to claim 17 or 18, wherein the transmission unit is further configured to send an indication message to the UE, the indication message is used to indicate the transmission of the CSI-RS and/or the transmission of the Information about the REs of the DM-RS. 20. The device according to claim 17, wherein the transmission unit is specifically configured to transmit CSI-RS on some or all of the reserved REs, or transmit the CSI-RS on the reserved REs and A preset number of REs are selected from the REs of the downlink data, and the CSI-RS sent to the UE is transmitted on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs. 21. The apparatus according to claim 17, wherein the reserving unit is specifically configured to reserve REs in the REs used to transmit DM-RS included in the subband configured for the UE; and/or When sending the downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data included in the subband of the other at least one UE. 22. The apparatus according to claim 21, wherein the reserved unit is specifically used to transmit downlink data included in the subband of the other at least one UE based on puncturing or rate matching REs are reserved in the REs. 23. The device according to claim 21, wherein the reservation unit is specifically used for the RE used to transmit the DM-RS contained in each PRB in the subband configured for the UE The number of REs reserved in the subband of the other UE is the same as the number of REs reserved in REs used to transmit downlink data contained in each PRB in the subband of the other UE. 24. The device according to any one of claims 17-18 or 20-23, wherein the reservation unit is specifically configured to reserve at least one pair of REs for transmitting DM-RSs REs, where each pair of REs refers to two REs that occupy the same frequency domain and are adjacent in the time domain. 25. The device according to any one of claims 17-18 or 20-23, wherein the transmission unit is specifically configured to periodically transmit information on the reserved RE or on the reserved RE Configure and transmit CSI-RS on REs and REs used for transmitting downlink data. 26. The apparatus according to claim 19, wherein, the indication message sent by the transmission unit is further used to instruct the UE to, in at least one subframe after receiving the indication message, in the reserved Obtain the CSI-RS and/or transmit the DM-RS on the above RE, or on the reserved RE and the RE used for transmitting downlink data. 27. A device for transmitting downlink signals, comprising: The resource obtaining unit is used to obtain the RE reserved by the network side in the resource unit RE used to transmit the downlink demodulation reference signal DM-RS, and transmit the obtained reserved RE to the signal obtaining unit; A signal obtaining unit, configured to obtain channel state information reference signals on the reserved REs, or on the reserved REs and the REs used to transmit downlink data according to the reserved REs transmitted by the resource obtaining unit CSI-RS. 28. The device according to claim 27, wherein the signal obtaining unit is further configured to obtain DM-RS and/or CSI-RS. 29. The device of claim 27 or 28, further comprising: a receiving unit, configured to receive an indication message from the network side for indicating the information of REs that transmit the CSI-RS and/or transmit the DM-RS; The resource obtaining unit is specifically configured to obtain REs reserved by the network side among REs used to transmit DM-RSs according to the received indication message; The signal obtaining unit is specifically configured to obtain the CSI-RS and /or obtain the DM-RS. 30. The device according to claim 27, wherein the signal obtaining unit is specifically configured to obtain CSI-RS on some or all of the reserved REs, or to obtain the CSI-RS on the reserved REs and for A preset number of REs are selected from REs transmitting downlink data, and CSI-RSs sent from the network side are obtained from the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs. 31. The device according to any one of claims 27-28 or 30, wherein the signal obtaining unit is specifically configured to periodically transmit information on the reserved RE, or on the reserved RE The CSI-RS is obtained from the uplink and the RE used for transmitting downlink data. 32. The device according to claim 29, wherein the signal obtaining unit is specifically configured to, in at least one subframe after receiving the indication message, set the Obtain a CSI-RS and/or obtain a DM-RS on the RE, or on the reserved RE and the RE used for transmitting downlink data. 33. A device for transmitting downlink signals, comprising: a signal processor, configured to reserve REs in resource elements RE used for transmitting downlink demodulation reference signals DM-RS, and transmit the reserved REs to the transceiver; The transceiver is configured to, according to the reserved REs transmitted by the signal processor, transmit channel state information reference signals on the reserved REs, or on the reserved REs and the REs used for transmitting downlink data CSI-RS. 34. The device according to claim 33, wherein the transceiver is further configured to transmit DM-RSs and/or CSI-RS. 35. The device according to claim 33, wherein the transceiver is specifically configured to transmit the CSI-RS on some or all of the reserved REs, or to transmit the CSI-RS on the reserved REs and for A preset number of REs are selected from the REs for transmitting downlink data, and the CSI-RS sent to the UE is transmitted on the selected preset number of REs, where the preset number is less than or equal to the number of reserved REs. 36. The device according to claim 33, wherein the signal processor is specifically configured to reserve REs in the REs used to transmit DM-RSs included in the subband configured for the UE; and/or When sending the downlink reference signal to the UE and at least one other UE occupying a different part of the system bandwidth, reserve REs in the REs used to transmit downlink data included in the subband of the other at least one UE. 37. A terminal device, characterized by comprising: The signal processor is configured to obtain the RE reserved by the network side in the resource element RE used to transmit the downlink demodulation reference signal DM-RS, and transmit the obtained reserved RE to the transceiver; The transceiver is configured to obtain channel state information reference signals on the reserved REs, or on the reserved REs and the REs used to transmit downlink data according to the reserved REs transmitted by the signal processor CSI-RS.