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EP-4740569-A1 - PHASE COMPENSATION FOR COHERENT JOINT TRANSMISSION

EP4740569A1EP 4740569 A1EP4740569 A1EP 4740569A1EP-4740569-A1

Abstract

Methods, systems, and devices for wireless communications are described. A group of transmission-reception points (TRPs) may be configured for joint transmissions to a user equipment (UE). At least one of the TRPs may be a reference TRP, and the UE may receive reference signaling from the reference TRP within multiple slots. The UE identifies one or more phase jumps associated with the reference signaling, where a phase jump includes a difference between a phase of the reference signaling received by the UE during a first slot and a phase of the reference signaling received by the UE during a subsequent slot. The UE transmits, to a network entity, a report including information that is based on the one or more phase jumps, which may support the reception by the UE of one or more joint transmissions from the group of TRPs.

Inventors

  • XIAO, Kexin
  • HUANG, YI
  • ZHANG, YU
  • WANG, Runxin
  • LY, Hung Dinh

Assignees

  • QUALCOMM Incorporated

Dates

Publication Date
20260513
Application Date
20230703

Claims (20)

  1. An apparatus for wireless communication, comprising: memory; a transceiver; and at least one processor of a user equipment (UE) , the at least one processor coupled with the memory and configured to cause the apparatus to: receive, via the transceiver, reference signaling from at least one reference transmission-reception point (TRP) during a plurality of slots, the at least one reference TRP included in a group of TRPs configured for joint transmissions to the UE; identify one or more phase jumps associated with the reference signaling, wherein a phase jump of the one or more phase jumps comprises a difference between a phase of the reference signaling as received by the UE during a first slot of the plurality of slots and a phase of the reference signaling as received by the UE during a subsequent slot of the plurality of slots; transmit, via the transceiver to a network entity, a report comprising information that is based at least in part on the one or more identified phase jumps; and receive, via the transceiver, a joint transmission from the group of TRPs based at least in part on the information included in the report.
  2. The apparatus of claim 1, the at least one processor further configured to cause the apparatus to: determine one or more channel state information metrics based at least in part on the one or more phase jumps, wherein the report comprises a channel state information report, and wherein the information comprises the one or more channel state information metrics that are based at least in part on the one or more phase jumps.
  3. The apparatus of claim 2, wherein the one or more channel state information metrics comprise a pre-coding matrix indicator value that is based at least in part on the one or more phase jumps, a channel quality indicator value that is based at least in part on the one or more phase jumps, a rank indicator value that is based at least in part on the one or more phase jumps, or any combination thereof.
  4. The apparatus of claim 1, wherein the report indicates the one or more phase jumps.
  5. The apparatus of claim 4, wherein: to indicate the one or more phase jumps, the report indicates a respective phase differential value, relative to a reference slot among the plurality of slots, for each other slot among the plurality of slots, and the respective phase differential value for a slot corresponds to a difference between a phase of the reference signaling as received by the UE within the slot and a phase of the reference signaling as received by the UE within the reference slot.
  6. The apparatus of claim 4, the at least one processor further configured to cause the apparatus to: determine one or more channel state information metrics independent of the one or more phase jumps; and indicate, via the report or a second report, the one or more channel state information metrics separately from the one or more phase jumps.
  7. The apparatus of claim 1, wherein, to receive the reference signaling from the at least one reference TRP, the at least one processor is configured to cause the apparatus to: receive, via the transceiver, the reference signaling from a same set of one or more reference ports of the at least one reference TRP within each slot of the plurality of slots.
  8. The apparatus of claim 7, the at least one processor further configured to cause the apparatus to: receive, via the transceiver, signaling that indicates, to the UE, the at least one reference TRP and the set of one or more reference ports for receiving the reference signaling.
  9. The apparatus of claim 7, the at least one processor further configured to cause the apparatus to: identify the at least one reference TRP from among the group of TRPs based at least in part on receiving the reference signaling from the at least one reference TRP prior to receiving other reference signaling from one or more other TRPs included in the group of TRPs; and identify the one or more reference ports based at least in part on the one or more reference ports being associated with one or more port identities (IDs) that are lower than one or more other port IDs associated with one or more other ports of the at least one reference TRP.
  10. The apparatus of claim 1, the at least one processor further configured to cause the apparatus to: receive, via the transceiver, other reference signaling from one or more other TRPs included in the group of TRPs, wherein the reference signaling received from the at least one reference TRP is frequency division multiplexed, time division multiplexed, code division multiplexed, or any combination thereof relative to the other reference signaling.
  11. The apparatus of claim 10, wherein the at least one processor is configured to cause the apparatus to: in a first subset of slots among the plurality of slots, receive the reference signaling from the at least one reference TRP and the other reference signaling from at least one of the one or more other TRPs; and in a second subset of slots among the plurality of slots, receive the reference signaling from the at least one reference TRP and not receive the other reference signaling from any of the one or more other TRPs.
  12. The apparatus of claim 1, the at least one processor further configured to cause the apparatus to: transmit, via the transceiver to the network entity, a capability report indicating an inability of the UE to maintain phase coherence when receiving reference signaling during multiple slots, wherein the at least one processor is configured to cause the apparatus to receive the reference signaling from the at least one reference TRP during the plurality of slots based at least in part on the capability report indicating the inability of the UE to maintain phase coherence when receiving reference signaling during multiple slots.
  13. The apparatus of claim 1, wherein the at least one processor is configured to cause the apparatus to receive the reference signaling from the at least one reference TRP during the plurality of slots based at least in part on a quantity of slots associated with channel state information reference signaling from the group of TRPs satisfying a threshold.
  14. An apparatus for wireless communication, comprising: memory; and at least one processor of a network entity, the at least one processor coupled with the memory and configured to cause the apparatus to: transmit, via at least one reference transmission-reception point (TRP) , reference signaling to a user equipment (UE) during a plurality of slots, the at least one reference TRP included in a group of TRPs configured for joint transmissions to the UE; receive, from the UE, a report comprising information that is based at least in part on one or more phase jumps associated with the reference signaling, wherein a phase jump of the one or more phase jumps comprises a difference between a phase of the reference signaling as received by the UE during a first slot of the plurality of slots and a phase of the reference signaling as received by the UE during a subsequent slot of the plurality of slots; and transmit, via the group of TRPs, a joint transmission to the UE based at least in part on the information included in report.
  15. The apparatus of claim 14, wherein the report comprises a channel state information report and the information comprises one or more channel state information metrics that are based at least in part on the one or more phase jumps, and wherein, to transmit joint transmission via the group of TRPs, the at least one processor is further configured to cause the apparatus to: transmit the joint transmission using a common phase configuration for each TRP of the group of TRPs.
  16. The apparatus of claim 14, wherein the report indicates the one or more phase jumps, and wherein, to transmit joint transmission via the group of TRPs, the at least one processor is further configured to cause the apparatus to: transmit the joint transmission using respective phase configurations for the TRPs in the group of TRPs, wherein the respective phase configurations are different for at least two TRPs in the group of TRPs and are based at least in part on the one or more phase jumps.
  17. The apparatus of claim 14, wherein, to transmit the reference signaling via the at least one reference TRPs, the at least one processor is further configured to cause the apparatus to: transmit the reference signaling via a same set of one or more reference ports of the at least one reference TRP within each slot of the plurality of slots.
  18. The apparatus of claim 14, the at least one processor further configured to cause the apparatus to: transmit other reference signaling via one or more other TRPs included in the group of TRPs, wherein the reference signaling transmitted via the at least one reference TRP is frequency division multiplexed, time division multiplexed, code division multiplexed, or any combination thereof relative to the other reference signaling.
  19. The apparatus of claim 18, wherein the at least one processor is configured to cause the apparatus to: in a first subset of slots among the plurality of slots, transmit the reference signaling via the at least one reference TRP and the other reference signaling via at least one of the one or more other TRPs; and in a second subset of slots among the plurality of slots, transmit the reference signaling via the at least one reference TRP and not transmit the other reference signaling via any of the one or more other TRPs.
  20. The apparatus of claim 18, wherein the at least one processor is configured to cause the apparatus to: transmit the reference signaling via first resources; and transmit the other reference signaling via second resources that are included in a same reference signal resource set as the first resources.

Description

PHASE COMPENSATION FOR COHERENT JOINT TRANSMISSION FIELD OF TECHNOLOGY The following relates to wireless communications, including phase compensation for coherent joint transmission (CJT) . BACKGROUND Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations, each supporting wireless communication for communication devices, which may be known as user equipment (UE) . SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support phase compensation for coherent joint transmission (CJT) from a group of transmission-reception points (TRPs) to a user equipment (UE) . For example, the described techniques provide for identifying phase jumps associated with reference signaling between one slot and another slot. To account for the phase jumps, the UE may provide a report (e.g., a channel state information (CSI) report) that compensates for the phase jumps or indicates the phase jumps to the network entity, so that the network entity may optimally configure the group of TRPs (e.g., by compensating for the phase jumps) for one or more subsequent joint transmission to the UE. A method for wireless communication by a UE is described. The method may include receiving reference signaling from at least one reference TRP within a set of multiple slots, the at least one reference TRP included in a group of TRPs configured for joint transmissions to the UE, identifying one or more phase jumps associated with the reference signaling, where a phase jump of the one or more phase jumps includes a difference between a phase of the reference signaling as received by the UE during a first slot of the set of multiple slots and a phase of the reference signaling as received by the UE during a subsequent slot of the set of multiple slots, transmitting, to a network entity, a report including information that is based on the one or more identified phase jumps, and receiving a joint transmission from the group of TRPs based on the information included in the report. An apparatus (e.g., a UE) for wireless communication is described. The apparatus may include memory (e.g., one or more memories) , a transceiver, and at least one processor coupled with the memory. The at least one processor may be configured (e.g., by the one or more processors individually or collectively executing code stored by the memory) to cause the apparatus to receive reference signaling from at least one reference TRP within a set of multiple slots, the at least one reference TRP included in a group of TRPs configured for joint transmissions to the apparatus, identify one or more phase jumps associated with the reference signaling, where a phase jump of the one or more phase jumps includes a difference between a phase of the reference signaling as received by the apparatus during a first slot of the set of multiple slots and a phase of the reference signaling as received by the apparatus during a subsequent slot of the set of multiple slots, transmit, to a network entity, a report including information that is based on the one or more identified phase jumps, and receive a joint transmission from the group of TRPs based on the information included in the report. Another apparatus (e.g., a UE) for wireless communication is described. The apparatus may include means for receiving reference signaling from at least one reference TRP within a set of multiple slots, the at least one reference TRP included in a group of TRPs configured for joint transmissions to the apparatus, means for identifying one or more phase jumps associated with the reference signaling, where a phase jump of the one or more phase jumps includes a difference between a phase of the reference signaling as received by the apparatus during a first slot of the set of multiple slots and a  phase of the reference signaling as received by the apparatus during a subsequent slot of the set of multiple slots, means for transmitting, to a network entity, a report including information that is based on the one or more identified phase jumps, and means for receiving a jo