HK1188896A - Signaling for downlink coordinated multipoint in a wireless communication system - Google Patents

Description

Signaling for downlink coordinated multipoint in a wireless communication system

Cross Reference to Related Applications

The benefit of priority from U.S. provisional patent application No. 61/646,223 entitled "advanced wireless communication system and technology" filed on 5, 11, 2012, the entire disclosure of which is incorporated herein by reference.

Technical Field

Embodiments of the present invention relate generally to the field of communications, and more specifically to signaling for downlink coordinated multipoint communications in a wireless communication system.

Background

Coordinated multipoint (CoMP) systems have been developed in order to improve various operating parameters in wireless networks. There are three types of CoMP systems: joint Transmission (JT); dynamic Point Selection (DPS); and coordinated scheduling and coordinated beamforming (CS/CB). In JT CoMP, both a serving point (e.g., an enhanced node base station (eNB)) and a coordinating point (e.g., another eNB) may transmit the same data to a User Equipment (UE). In DPS CoMP, a transmission point may be dynamically selected among different candidates, e.g., a macro node eNB and a pico node eNB. In CS/CB CoMP, a coordinating node may suppress interference of an interfering channel. However, the eNB may not have sufficient control and signaling mechanisms for efficient management of CoMP communications with the UE.

Drawings

The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals refer to like structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Fig. 1 schematically illustrates a wireless communication network including a User Equipment (UE) and a plurality of evolved node bs (enbs), in accordance with various embodiments.

Fig. 2 is a table that maps values of a Channel State Information (CSI) request field to trigger aperiodic CSI feedback in accordance with various embodiments.

Fig. 3 is a table that maps values of another CSI request field, in accordance with various embodiments.

Fig. 4 illustrates a bitmap that may be used to indicate one or more CSI processes included in a set of CSI processes for triggering aperiodic CSI feedback, in accordance with various embodiments.

Fig. 5 is a flow diagram illustrating a method for triggering aperiodic CSI feedback that may be performed by a UE, in accordance with various embodiments.

Fig. 6 is a table mapping values of cell-specific reference signal (CRS) configuration parameters to corresponding values of a number of CRS antenna ports and CRS frequency shifts, in accordance with various embodiments.

Fig. 7 schematically depicts an example system in accordance with various embodiments.

Detailed Description

Illustrative embodiments of the present disclosure include, but are not limited to, methods, systems, computer-readable media and apparatuses for signaling in a wireless communication network to support downlink coordinated multipoint communication.

The various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that alternative embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials, and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that alternative embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.

Further, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the illustrative embodiments; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.

The phrase "in some embodiments" is used repeatedly. The phrase generally does not refer to the same embodiment; however, it may refer to the same embodiment. The terms "comprising," "having," and "including" are synonymous, unless the context dictates otherwise. The phrase "A and/or B" means (A), (B) or (A and B). The phrase "A/B" means (A), (B), or (A and B), similar to the phrase "A and/or B". The phrase "at least one of A, B and C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). The phrase "(A) B" means (B) or (A and B), i.e., A is optional.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the embodiments of the present disclosure. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments of the present disclosure be limited only by the claims and the equivalents thereof.

As used herein, the term "module" may refer to, be part of, or include the following: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

Fig. 1 schematically illustrates a wireless communication network 100 in accordance with various embodiments. The wireless communication network 100 (hereinafter, "network 100") may be an access network of a 3 rd generation partnership project (3 GPP) Long Term Evolution (LTE) network, such as an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or the like. The network 100 may include a base station, such as an enhanced node base station (eNB) 104, configured to wirelessly communicate with a User Equipment (UE) 108.

At least initially, the eNB 104 may have an established wireless connection with the UE 108 and may operate as a serving node within the CoMP measurement set. One or more additional enbs (e.g., enbs 112 and 116) of network 100 may also be included in the CoMP measurement set. The enbs 112 and 116 may be configured to facilitate wireless communication with the UE 108 by coordinating with the eNB 104. The one or more additional enbs may be collectively referred to as a "coordinating node. The eNB may transition between coordinating and serving node roles.

The serving node and the coordinating node may communicate with each other via a wireless connection and/or a wired connection (e.g., a high-speed fiber backhaul connection).

The enbs may each have substantially the same transmission power capability as one another, or alternatively, some of the enbs may have relatively low transmission power capabilities. For example, in one embodiment, eNB 104 may be a relatively high power base station, e.g., a macro eNB, while enbs 112 and 116 may be relatively low power base stations, e.g., pico enbs and/or femto enbs.

The eNB 104 may be configured to communicate with the UE 108 over one or more component carriers. Each component carrier may be associated with a frequency band for communication on that component carrier. Individual component carriers may be considered as separate cells in some embodiments. In some embodiments, the eNB 104 may communicate with the UE 108 over multiple component carriers (with different frequencies) using carrier aggregation. The UE 108 may receive control information on the primary serving cell and may receive other information on the secondary serving cell. The primary and secondary serving cells may be associated with respective component carriers. Carrier aggregation may be used in addition to, or instead of, CoMP communication.

The UE 108 may include a communication module 120 and a feedback module 124 coupled to each other. UE 108 may further include a CoMP module 128 coupled with communication module 120 and/or feedback module 124. The communication module 120 may further be coupled with one or more of the plurality of antennas 132 of the UE 108 for wireless communication over the network 100.

The UE 108 may include any suitable number of antennas. In various embodiments, UE 108 may include at least as many antennas as the number of synchronized spatial layers or streams (simultaneous spatial layers or streams) received by UE 108 from the eNB, although the scope of the disclosure may not be limited in this respect. The number of synchronized spatial layers or streams may also be referred to as a transmission rank, or simply rank.

One or more of the antennas 132 may alternately be used as a transmit or receive antenna. Alternatively or additionally, one or more of the antennas 132 may be dedicated receive antennas or dedicated transmit antennas.

eNB 104 may include at least a communication module 136, a CoMP management module 140, and an aperiodic feedback module 144 coupled to each other as shown. The communication module 136 may further be coupled with one or more of the plurality of antennas 152 of the eNB 104. The communication module 136 may communicate (e.g., transmit and/or receive) with one or more UEs (e.g., UE 108). In various embodiments, eNB 104 may include at least as many antennas as the number of synchronized transmission streams transmitted to UE 108, although the scope of the disclosure may not be limited in this respect. One or more of the antennas 152 may alternately be used as transmit or receive antennas. Alternatively or additionally, one or more of the antennas 152 may be dedicated receive antennas or dedicated transmit antennas.

In various embodiments, the UE 108 may be configured with one or more CSI processes for individual cells (e.g., component carriers). The CSI process may include associated CSI reference signal (CSI-RS) resources and/or associated CSI interference measurement (CSI-IM) resources. In some embodiments, the CSI-RS resources may be non-zero power (NZP) CSI-RS resources. The UE 108 may further receive a cell index and/or CSI process Identifier (ID) associated with each configured CSI process (e.g., within a given cell). The UE 108 may be configured with one or more CSI processes (e.g., by the eNB 104) using higher layer signaling (e.g., via Radio Resource Control (RRC) signaling). The CSI process may be used by the UE 108 to generate CSI feedback to the eNB 104 to facilitate downlink CoMP communications with the UE 108.

In various embodiments, the feedback module 124 of the UE 108 may receive a Downlink Control Information (DCI) message from the eNB 104 via the communication module 120. The DCI message may be received, for example, on a Physical Downlink Control Channel (PDCCH). In some embodiments, the PDCCH may be enhanced PDCCH (epdcch) or other types of PDCCH. The DCI message may include a CSI request field to indicate one or more CSI processes for which the UE 108 provides CSI feedback to the eNB 104. Thus, the DCI message may facilitate aperiodic reporting of CSI feedback by the UE 108. In some embodiments, the CSI request field may be two bits to indicate one of four possible values. Other embodiments of the CSI request field may include other numbers of bits.

The feedback module 124 may generate CSI feedback for the indicated CSI process. The CSI feedback may include, for example, a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), one or more selected subbands, and/or a Rank Indicator (RI) for the CSI process. The feedback module 124 may then transmit a CSI report including the generated CSI feedback to the eNB 104 via the communication module 120. The CSI report may be transmitted, for example, on a Physical Uplink Shared Channel (PUSCH).

Fig. 2 illustrates a table 200 that maps values of a two-bit CSI request field, in accordance with some embodiments. As shown in table 200, the CSI request field may have a value of "01" to indicate that the feedback module 124 is to provide CSI reports for a first set of CSI processes configured for the serving cell of the UE 108. The serving cell may be a primary serving cell on which the UE 108 receives DCI including a CSI request field. In some embodiments, the UE 108 may identify the serving cell for which the UE 108 is to provide CSI feedback based on the component carrier on which the UE 108 receives the DCI.

In some embodiments, a value of "01" may indicate that the UE 108 is to provide CSI feedback for all of the CSI processes associated with the serving cell (e.g., the first set of CSI processes may include all CSI associated with the serving cell). In other embodiments, the first set of CSI processes may include a subset (e.g., less than all) of the CSI processes associated with the serving cell. For example, the first set of CSI processes may be configured for the UE 108 via higher layers (e.g., via RRC signaling).

In various embodiments, the CSI request field may have a value of "10" for indicating that feedback module 124 is to provide CSI reports for the second set of CSI processes. Alternatively, the CSI request field may have a value of "11" for indicating that the feedback module 124 is to provide CSI reports for a third set of CSI processes. The second and/or third sets of CSI processes may be configured by higher layers (e.g., RRC signaling), such as by the eNB 104, to indicate the CSI processes included in the second and/or third sets.

The CSI reports for the first, second, and/or third groups may be used by the eNB 104 to manage downlink CoMP communications with the UE 108. In some embodiments, the CSI reports for the first, second, and/or third groups may be used by the eNB 104 to manage carrier aggregation communications with the UE 108 in addition to CoMP communications. The CSI request field may be similar to a CSI request field used to trigger CSI reporting to support carrier aggregation communication. However, the CSI request field for carrier aggregation may only trigger CSI reporting for one CSI process for a particular cell or group of cells, and may not allow triggering CSI reporting for more than one CSI process associated with a given cell and/or associated with different cells. Further, the second and/or third sets of CSI processes may include CSI processes on different cells having the same frequency (e.g., cells having the same frequency transmitted by different enbs).

In some embodiments, the CSI request field as described herein may be used when configuring the UE 108 in transmission mode 10 (as defined in LTE release-advanced 11). Transmission mode 10 may support CoMP communications with a UE. In transmission mode 10, the UE 108 may provide CSI feedback for one or more CSI processes as described herein. The UE 108 may receive the scheduling information using DCI format 2D. In some embodiments, DCI format 1A may be used as the fallback mode. The UE 108 may also receive PDSCH mapping parameters for cells other than the serving cell. Additionally or alternatively, the UE 108 may use a specific UE-specific reference signal for demodulation of the PDSCH.

The second and/or third sets of CSI processes may include any number of one or more CSI processes. In some embodiments, the second and/or third groups may include CSI processes. In some embodiments, the second and third sets may include one or more common CSI processes (e.g., one or more CSIs included in both the second and third sets). In other embodiments, the second and third groups may each include only one CSI process. The CSI processes of the second and/or third sets may include one or more CSI processes associated with a cell different from the serving cell. Additionally or alternatively, the second and/or third groups may include multiple CSI processes associated with different cells.

In various embodiments, the CSI request field may include a value of "00" to indicate that the DCI message does not trigger an aperiodic CSI report. The value "00" may be used, for example, when transmitting a DCI message to the UE 108 for another purpose other than triggering an aperiodic CSI report.

Although specific values for the two-bit CSI request field are shown in table 200, it will be apparent that these values may be mapped in any suitable manner to corresponding actions that may be different than those shown in table 200. For example, in another embodiment, a value of "00" may trigger CSI reporting for the first set of CSI processes.

As described herein, the CSI request field may be used by the eNB 104 to trigger CSI reporting for the first set of CSI processes. The eNB 104 may dynamically change the set of CSI processes for which the eNB 104 requests CSI feedback from the UE 104. Aperiodic feedback module 144 of eNB 104 can receive the CSI reports and CoMP management module 140 can manage downlink CoMP communications with the UE using CSI feedback information included in the CSI reports.

In other embodiments, the CSI request field may include only one bit. The bit may have a first value (e.g., "1") for triggering CSI reporting for all CSI processes of the serving cell. The bit may have a second value (e.g., "0") if the DCI message does not trigger a CSI report. The one-bit CSI request field may be used, for example, when the UE 108 uses a transmission mode in which there is a common search space (e.g., different from the UE-specific search space) for PDCCH decoding.

Fig. 3 illustrates a table 300 mapping values of a two-bit CSI request field according to another embodiment. As shown in fig. 3, the two-bit CSI request field may include a value of "01" to indicate that the UE 108 is to provide CSI reports for a first set of CSI processes, or a value of "10" to indicate that the UE 108 is to provide CSI reports for a second set of CSI processes. The CSI request field may further include a value of "11" to indicate that the UE 108 is to provide CSI reports for both the first and second sets of processes. The CSI request field may include a value of "00" for indicating that the DCI message does not trigger an aperiodic CSI report.

It will be apparent that other suitable configurations of the CSI request field, in addition to the configurations shown in fig. 2 and 3, may be used to trigger aperiodic CSI reporting for different sets of CSI processes. For example, in another embodiment, the CSI request field may be similar to that shown in table 300, but where a value of "00" indicates that the UE 108 is to provide CSI reports for a set of CSI processes configured for the serving cell.

In various embodiments, the CSI process sets (e.g., the first, second, and/or third sets described above) that may be triggered by the CSI request field for CSI reporting may be configured by the eNB 104 using a corresponding bitmap. These bitmaps may be transmitted by the eNB 104 (e.g., via RRC signaling) to the UE 108 to indicate which CSI processes are included in a given CSI process group. For example, fig. 4 illustrates a bitmap 400 according to various embodiments. Bitmap 400 includes a plurality of bits (e.g., bit b)₀、b₁、…b_NK-1) And the individual bits may correspond to individual CSI processes to indicate whether the CSI processes are included in a CSI process group defined by the bitmap 400. Bits may be ordered in the bitmap 400 according to bit index (e.g., in ascending order of cell index), and bits corresponding to CSI processes associated with the same cell index may be ordered by their respective CSI IDs. For example, the bitmap 400 includes bits corresponding to K +1 component carriers (e.g., having a cell index of 0 through a cell index of K). Each component carrier may include a maximum of N configured CSI processes. The bit groups corresponding to CSI processes with the same cell index are arranged in bitmap 400 in ascending order of cell index (e.g., where the bit (b) of the CSI process corresponding to cell index 0₀- b_N-1) At bit (b) of the CSI process corresponding to cell index 1_N- b_2N-1) Previously set in bitmap 400). The bits are ordered in ascending order of CSI process IDs at bit groups corresponding to CSI processes having the same cell index. E.g. bit b₀Corresponding to a CSI process with a cell index of 0 and a CSI process ID of 0, and bit b₁Corresponding to a CSI process with cell index 0 and CSI process ID 1, etc.

As discussed above, the eNB 104 may transmit multiple bitmaps similar to bitmap 400 to define different CSI process groups for aperiodic CSI reporting. Aperiodic CSI reporting for individual groups may then be triggered by a DCI message that includes a CSI request field as described herein. In some embodiments, a bitmap for defining CSI process groups for aperiodic CSI reporting may be transmitted as part of the CSI process configuration process (e.g., when the UE 108 becomes RRC connected with the eNB 104). For example, CoMP management module 140 of eNB 104 may transmit the bitmap concurrently with CSI process configuration information (e.g., CSI-RS resources and/or CSI-IM resources) for individual CSI processes. Additionally or alternatively, the bitmap may be transmitted separately from CSI process configuration information to define and/or modify CSI process groups for aperiodic CSI reporting.

In some embodiments, CoMP management module 140 of eNB 104 may further transmit a codebook subsetreestiction parameter associated with the individual CSI processes. The codebook subsetreestiction parameter may be transmitted as part of the configuration of the CSI process. The codebook subsetreestiction parameter may indicate a subset of PMIs within a codebook to be used by the UE 104 for CSI reporting of a respective CSI process. Alternatively or additionally, a codebook subsetrestation parameter may be configured for each NZP CSI-RS resource and/or subset of subframes.

In some embodiments, the eNB 104 may configure one or more CSI dependencies among a plurality of configured CSI processes. For example, the eNB 104 may instruct the UE 108 to report CSI feedback for multiple CSI processes on the same rank and/or over the same preferred subband.

As discussed above, the feedback module 124 of the UE 108 may generate CSI feedback for one or more CIS processes triggered by the CSI request field. The CSI feedback may be generated based on CSI-RS resources and/or CSI-IM resources configured for the CSI process. The CSI feedback may include, for example, a CQI, a PMI, one or more selected subbands, and/or an RI for the CSI process. The UE 108 may transmit CSI feedback to the eNB 104 in a CSI report.

In some embodiments, CSI feedback for multiple CSI processes may be concatenated in the same CSI report. For example, CSI feedback for multiple CSI processes may be concatenated according to the CSI process index and/or the cell index of the CSI process. In one embodiment, CSI feedback for CSI process groups associated with the same component carrier (e.g., having the same cell index) may be ordered in the CSI report in ascending order of cell index. The CSI feedback may be arranged within the individual groups in ascending order of CSI process indices of individual CSI processes having the same cell index.

In some cases, one or more components of CSI feedback for a first CSI process may be the same as one or more components of CSI feedback for a second CSI process. For example, the RI reported for the first and second CSI processes may be the same. In some embodiments, the shared component (e.g., RI in this example) may be omitted from the CSI report of the first CSI process or the second CSI process. This may reduce the bandwidth required for CSI reporting.

In some embodiments, the CSI report may be encoded using turbo coding and/or Cyclic Redundancy Check (CRC) coding. For example, turbo coding and/or CRC coding may be used to encode CQI and PMI reports. This may facilitate having a large payload length for CSI reports.

Fig. 5 is a flow diagram illustrating a method 500 for triggering aperiodic CSI feedback, in accordance with various embodiments. The method 500 may be performed by a UE (e.g., the UE 108). In some embodiments, the UE may include and/or have access to one or more computer-readable media having instructions stored thereon that, when executed, cause the UE to perform method 500. Additionally or alternatively, in some embodiments, the UE may include circuitry for performing the method 500.

At 504, the UE may receive a first bitmap (e.g., bitmap 400) from an eNB (e.g., eNB 104) over a wireless communication network (e.g., network 100). The first bitmap may indicate one or more CSI processes included in the first set of CSI processes. For example, the first bitmap may include a plurality of bits, and the individual bits may correspond to individual CSI processes to indicate whether CSI processes are included in the first set of CSI processes. The individual bit may have a first value (e.g., "1") for indicating that the corresponding CSI process is included in the first group, or a second value (e.g., "0") for indicating that the corresponding CSI process is not included in the first group. In some embodiments, the plurality of bits may be ordered in the bitmap according to a cell index of the CSI process (e.g., in ascending order of cell index), and the bits corresponding to CSI processes having the same cell index may be ordered by CSI process IDs of the CSI processes (e.g., in ascending order of CSI process IDs).

At 508, the UE may receive a second bitmap from the eNB. The second bitmap may indicate one or more CSI processes included in a second set of CSI processes. This second bitmap may have a similar bit setting as described above for the first bitmap, but with a different bit set to a first value (e.g., "1"). In some embodiments, the first and second groups may include one or more common CSI processes.

At 512, the UE may receive a DCI message from the eNB. The DCI message may include a CSI request field to request CSI feedback to support downlink CoMP transmission to the UE. In some embodiments, the CSI request field may include two bits for forming one of four values. The CSI request field may have a first value to indicate that the UE is to provide CSI feedback for a first set of CSI processes (e.g., configured at 504) or a second value to indicate that the UE is to provide CSI feedback for a second set of CSI processes (e.g., configured at 508).

At 516, the UE may generate CSI feedback for the CSI process indicated by the CSI request field.

At 520, the UE may transmit the generated CSI feedback to the eNB. The CSI feedback may be included in one or more CSI reports.

In some embodiments, the CSI request field may have a third value for indicating that the UE is to provide CSI feedback for a set of CSI processes configured for a serving cell of the UE. The serving cell may be identified by the carrier component on which the eNB transmits DCI including the CSI request field to the UE. The CSI process set configured for the serving cell may include all CSI processes configured for the serving cell or a subset of all CSI processes configured for the serving cell.

In some embodiments, the CSI request field may have a fourth value for indicating that the DCI message does not trigger a CSI report.

In other embodiments, the third or fourth value of the CSI request field may be used to indicate that the UE is to provide CSI feedback for both the first and second sets of CSI processes (e.g., as configured at 504 and 508, respectively).

In various embodiments, the UE 108 may receive information related to a Physical Downlink Shared Channel (PDSCH) resource element mapping configuration for use by the UE 108 to receive PDSCH. In some embodiments, CoMP module 128 of UE 108 may receive an RRC message from the eNB including PDSCH resource element mapping parameters of a plurality of PDSCH mapping configurations. The PDSCH resource element mapping parameters may include, for example, cell-specific reference signal (CRS) antenna port number, CRS antenna port shift, PDSCH starting symbol, multicast broadcast single frequency network subframe configuration for individual PDSCH mapping configuration. In some embodiments, the PDSCH resource element mapping parameters may further include a non-zero power CSI-RS identifier and/or a CSI process identifier associated with the PDSCH mapping configuration. The PDSCH mapping configuration may be further (explicitly or implicitly) associated with a PDSCH mapping configuration ID.

Any suitable number of PDSCH mapping configurations may be configured for the UE 108. For example, in one embodiment, four PDSCH mapping configurations may be configured for the UE 108. In some embodiments, the PDSCH mapping configuration may be generic (e.g., not associated with a particular cell). In other embodiments, the PDSCH mapping configurations may be associated with respective individual cells.

In some embodiments, the number of CRS antenna ports and CRS antenna port shifts may be jointly encoded within the CRS configuration parameters. For example, fig. 6 illustrates a table 600 showing that values of CRS configuration parameters map to corresponding values of CRS antenna port number and CRS antenna port shift. As shown in table 600, a first value (e.g., a value of 0) of the CRS configuration parameter may indicate that the PDSCH mapping configuration has 4 antenna ports and a CRS frequency shift of 2 subframes. In some embodiments, the PDSCH mapping configuration may have a number of antenna ports of 1, 2, or 4. A PDSCH mapping configuration with 1 antenna port may have one of six CRS frequency shifts (e.g., 0, 1, 2, 3, 4, or 5 subframes), while a PDSCH mapping configuration with 2 or 4 antenna ports may have one of three CRS frequency shifts (e.g., 0, 1, or 2 subframes). Thus, joint encoding of the CRS antenna port number and CRS antenna port shift may require one less bit than encoding them separately.

In various embodiments, the UE 108 may receive a DCI message from the eNB 104 indicating one of a PDSCH mapping configuration (e.g., a first PDSCH mapping configuration) of a plurality of PDSCH mapping configurations for use by the UE 108 to receive PDSCH. For example, the DCI message may include a PDSCH mapping configuration ID corresponding to one of the PDSCH mapping configurations configured using RRC signaling as described above. In some embodiments, the PDSCH mapping configuration ID may be jointly encoded with a component carrier indicator indicating a first component carrier (on which PDSCH is to be transmitted to UE 108) of the plurality of configured component carriers. For example, the DCI message may include a carrier aggregation Cell Identification Field (CIF) indicating a component carrier and PDSCH mapping configuration for use by the UE to receive PDSCH. In some embodiments, the CIF may be three bits. The three-bit CIF may have eight different values to indicate one of the two component carriers and one of the four PDSCH mapping configurations. In other embodiments, the PDSCH mapping configuration ID may be included in a separate field from the CIF.

The UE 108 may use the PDSCH resource element mapping parameters to receive PDSCH via CoMP communications. For example, PDSCH resource element mapping parameters may facilitate avoiding CRS collision with PDSCH. For Joint Transmission (JT) CoMP, the UE 108 may use the mapping parameters to determine the instantaneous rate matching mode when resource element muting (resource element sounding) is used to mitigate CRS from colliding with PDSCH. For Dynamic Point Selection (DPS), the mapping parameters may be used to avoid the need for resource element muting. In addition, for DPS in transmission modes 1, 2, 3 and 4, UE 108 may use PDSCH resource element mapping parameters to determine the specific CRS that should be used for PDSCH demodulation, as proposed in LTE-advanced standard release 11.

In embodiments in which PDSCH mapping configurations are associated with respective individual cells (component carriers), a transmitting cell may be indicated to the UE 108 to indicate the PDSCH mapping configuration for use by the UE to receive PDSCH. In some embodiments, carrier aggregation CIF may be used to indicate the transmitting cell of downlink CoMP (e.g., using values of CIF not used for carrier aggregation). It will be apparent that other bit sizes and/or settings may be used to indicate the PDSCH mapping configuration for use by the UE 108.

The eNB 104/112/116 and/or UE 108 described herein may be implemented in a system using any suitable hardware and/or software to configure as desired. Fig. 7 illustrates, for one embodiment, an example system 700 that includes one or more processors 704, system control logic 708 coupled with at least one of the processors 704, system memory 712 coupled with the system control logic 708, non-volatile memory (NVM)/storage 716 coupled with the system control logic 708, a network interface 720 coupled with the system control logic 708, and/or an input/output (I/O) device 732 coupled with the system control logic 708.

Processor 704 may include one or more single-core or multi-core processors. The processor 704 may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, baseband processors, etc.).

System control logic 708 for one embodiment may comprise any suitable interface controllers to provide any suitable interface to at least one of processors 704 and/or to any suitable device or component in communication with system control logic 708.

System control logic 708 for one embodiment may include one or more memory controllers to provide an interface to system memory 712. System memory 712 may be used to load and store data and/or instructions to, for example, system 700. System memory 712 for one embodiment may comprise any suitable volatile memory, such as suitable Dynamic Random Access Memory (DRAM), and the like.

NVM/storage 716 may include one or more tangible, non-transitory computer-readable media for storing data and/or instructions, for example. NVM/storage 716 may include any suitable non-volatile memory, such as flash memory, etc., and/or may include any suitable non-volatile storage device, such as one or more Hard Disk Drives (HDDs), one or more Compact Disk (CD) drives, and/or one or more Digital Versatile Disk (DVD) drives, for example.

NVM/storage 716 may include a storage resource that is physically part of a device on which system 700 is installed or that is accessible by, but not necessarily part of, the device. For example, NVM/storage 716 may be accessed over a network via network interface 720 and/or accessed via input/output (I/O) devices 732.

Network interface 720 may have a transceiver 722 to provide a radio interface for system 700 to communicate over one or more networks and/or with any other suitable device. Transceiver 722 may implement communication module 120 of UE 108 or communication module 136 of eNB 104. In various embodiments, transceiver 722 may be integrated with other components of system 700. For example, transceiver 722 may include a processor of processor 704, a memory of system memory 712, and a NVM/storage of NVM/storage 716. Network interface 720 may include any suitable hardware and/or firmware. Network interface 720 may include multiple antennas to provide a multiple-input multiple-output radio interface. Network interface 720 for one embodiment may include, for example, a wired network adapter (e.g., an Ethernet network adapter), a wireless network adapter, a telephone modem, and/or a wireless modem.

For one embodiment, at least one of the processors 704 may be packaged together with logic for one or more controllers of system control logic 708. For one embodiment, at least one of the processors 704 may be packaged together with logic for one or more controllers of system control logic 708 to form a System In Package (SiP). For one embodiment, at least one of the processors 704 may be integrated on the same chip as logic for one or more controllers of system control logic 708. For one embodiment, at least one of processors 704 may be integrated on the same chip with logic for one or more controllers of system control logic 708 to form a system on a chip (SoC). For one embodiment, at least one of the processors 704 may be packaged together with the memory of the NVM/storage 716 to form a package on package (PoP). For example, the memory may be coupled with an application processor and may be configured as a PoP with the application processor.

In various embodiments, I/O device 732 may include a user interface designed to enable a user to interact with system 700, a peripheral component interface designed to enable peripheral components to interact with system 700, and/or sensors designed to determine environmental conditions and/or location information related to system 700.

In various embodiments, the user interface may include, but is not limited to, a display (e.g., a liquid crystal display, a touch screen display, etc.), a speaker, a microphone, one or more capture devices (e.g., a camera and/or a video camera), a flash (e.g., a light emitting diode flash), and a keyboard.

In various embodiments, the peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a Universal Serial Bus (USB) port, an audio jack, and a power supply interface.

In various embodiments, the sensors may include, but are not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of network interface 720 or interact with network interface 720 to communicate with components of a positioning network, such as Global Positioning System (GPS) satellites.

In various embodiments, system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, a smartphone, and the like. In various embodiments, system 700 may have more or fewer components and/or different architectures.

Although certain embodiments have been illustrated and described herein for purposes of description, a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that the embodiments described herein be limited only by the claims and the equivalents thereof.

Claims (25)

1. Device for feedback of channel state information by user equipment UE

The device comprises:

a communication module configured to communicate with an evolved node B, eNB, over a wireless communication network

A message; and

a feedback module coupled to the communication module and configured to:

receiving, via the communication module, a downlink control information, DCI, message from the eNB, the DCI message comprising a two-bit channel state information, CSI, request field, wherein the CSI request field has:

a first value to indicate that the feedback module is to provide CSI reports for a first set of preconfigured CSI processes associated with a serving cell;

a second value to indicate that the feedback module is to provide CSI reports for a second set of preconfigured CSI processes; or

A third value to indicate that the feedback module is to provide a CSI report for a third set of preconfigured CSI processes; and

generating CSI feedback for a CSI process indicated by the CSI request field; and

transmitting, via the communication module, a CSI report to the eNB on a Physical Uplink Shared Channel (PUSCH), the CSI report including the generated CSI feedback.

2. The apparatus of claim 1, wherein the DCI message is a first DCI message, and wherein the feedback module is further configured to receive a second DCI message including a CSI request field having a fourth value to indicate that the second DCI message does not trigger a CSI report.

3. The apparatus of claim 1, wherein the second and third sets of CSI processes are configured for the UE via radio resource control, RRC, signaling.

4. The apparatus of claim 3, wherein the first group comprises a subset of less than all CSI processes associated with the serving cell configured for the UE via Radio Resource Control (RRC) signaling.

5. The apparatus of claim 4, wherein the UE is configured, via RRC signaling, a subset of CSI processes associated with a respective one of a plurality of cells including the serving cell, and wherein the UE is to identify a first set of preconfigured CSI processes for the serving cell based on receiving the DCI message on the serving cell.

6. The apparatus of claim 3, wherein the first group includes all CSI processes associated with the serving cell.

7. The apparatus of claim 1, wherein the second and third sets of preconfigured CSI processes comprise one or more common CSI processes.

8. The apparatus of claim 1, wherein the generated CSI feedback comprises a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), one or more selected subbands, or a Rank Indicator (RI); and

wherein the individual CSI processes are associated with CSI reference signal (CSI-RS) resources and CSI interference measurement (CSI-IM) resources.

9. The apparatus of any of claims 1-8, wherein the CSI feedback supports downlink coordinated multipoint (CoMP) transmission to the UE.

10. The apparatus of any of claims 1-8, wherein the CSI report comprises CSI feedback for a plurality of CSI processes concatenated in ascending order of CSI process index.

11. An apparatus to be employed by an evolved node B, eNB, of a wireless communication network, the apparatus comprising:

a coordinated multipoint (CoMP) module configured to manage downlink CoMP communications with a User Equipment (UE) through the wireless communications network; and

an aperiodic feedback module coupled to the CoMP module and configured to:

transmitting a downlink control information, DCI, message to the UE, the DCI message comprising a two-bit channel state information, CSI, request field, wherein the CSI request field has:

a first value to indicate that the UE is to provide CSI reporting for a first set of preconfigured CSI processes associated with a serving cell;

a second value to indicate that the UE is to provide CSI reports for a second set of preconfigured CSI processes; or

A third value to indicate that the UE is to provide CSI reports for a third set of preconfigured CSI processes; and

receiving a CSI report from the UE on a Physical Uplink Shared Channel (PUSCH), the CSI report including CSI feedback for a CSI process identified by the CSI request field, wherein the CSI report supports downlink CoMP communications with the UE.

12. The apparatus of claim 11, wherein the DCI message is a first DCI message, and wherein the aperiodic feedback module is further configured to receive a second DCI message including a CSI request field with a fourth value for indicating that the second DCI message does not trigger a CSI report.

13. The apparatus of claim 11, wherein the first group includes a subset of less than all CSI processes associated with the serving cell.

14. The apparatus of any of claims 11-13, wherein the second and third sets of preconfigured CSI processes comprise one or more common CSI processes.

15. The apparatus of claim 11, wherein the CoMP management module is further configured to configure individual CSI processes at the UE via higher layer signaling, and wherein the CoMP management module is further configured to transmit a codebook subsetrestiction parameter associated with an individual CSI process to indicate a subset of precoding matrix indicators within a codebook to be used by the UE for CSI reporting.

16. An apparatus to be employed by a user equipment, UE, the apparatus comprising:

means for receiving, over a wireless communication network, a first bitmap from an evolved node B, eNB, the first bitmap indicating one or more CSI processes included in a first set of CSI processes;

means for receiving a second bitmap from the eNB indicating one or more CSI processes included in a second set of CSI processes;

means for receiving a downlink control information, DCI, message from the eNB, the DCI message comprising a two-bit channel state information, CSI, request field for requesting CSI feedback to support downlink coordinated multipoint, CoMP, transmission to a UE, wherein the CSI request field has:

a first value to indicate that the UE is to provide CSI feedback for the first set of CSI processes; or

A second value to indicate that the UE is to provide CSI feedback for the second set of CSI processes; and

generating CSI feedback for a CSI process indicated by the CSI request field; and

transmitting a CSI report including the generated CSI feedback to the eNB.

17. The apparatus of claim 16, wherein the DCI message is a first DCI message, and wherein the apparatus further comprises means for receiving a second DCI message including a CSI request field having a third value for indicating that the UE is to provide CSI reports for a third set of CSI processes configured for a serving cell.

18. The apparatus of claim 17, further comprising means for receiving a third DCI message including a CSI request field having a fourth value for indicating that the third DCI message does not trigger a CSI report.

19. The apparatus of claim 16, wherein the DCI message is a first DCI message, and wherein the apparatus further comprises means for receiving a second DCI message including a CSI request field having a third value for indicating that the UE is to provide CSI reports for a first set and a second set of CSI processes.

20. The apparatus of claim 16, wherein the first bitmap comprises a plurality of bits, wherein a number of bits corresponds to an individual CSI process to indicate whether the CSI process is included in the first set of CSI processes, wherein the plurality of bits are ordered in a bitmap according to a cell index, and wherein a number of bits corresponding to CSI processes associated with a same cell index are ordered by CSI process Identifier (ID).

21. A method employed by a user equipment, UE, of a wireless communication network, comprising:

receiving configuration information relating to an individual channel state information, CSI, process for use by the UE to report CSI feedback to support downlink CoMP transmissions to the UE;

generating CSI feedback for a plurality of configured CSI processes;

generating a CSI report comprising CSI feedback of the plurality of configured CSI processes concatenated according to CSI process indices of the CSI processes; and

transmitting the CSI report to an evolved node B (eNB) of the wireless communication network.

22. The method of claim 21, wherein the CSI reports comprise CSI feedback for CSI processes with different component carriers, wherein the CSI feedback comprises Channel Quality Indicators (CQIs), Precoding Matrix Indicators (PMIs), or Rank Indicators (RIs), and wherein the CSI feedback is concatenated first in ascending order of CSI process indices for CSI processes of a given cell and then in ascending order of cell indices.

23. The method of claim 21, wherein the CSI report comprises CSI feedback for a first CSI process and a second CSI process, and wherein a shared component of the same CSI feedback for the first and second CSI processes is reported only once in the CSI report.

24. The method of claim 23, wherein the shared component is a Rank Indicator (RI) associated with the first and second CSI processes.

25. The method of claim 20, wherein the CSI report is encoded using turbo coding and Cyclic Redundancy Check (CRC) coding.