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CN-122029764-A - Method for channel state information measurement and reporting for multiple CSI sub-configurations for network power saving

CN122029764ACN 122029764 ACN122029764 ACN 122029764ACN-122029764-A

Abstract

Methods and apparatus in a wireless network provide channel state information, CSI, reporting that omits information based on multiple sub-configurations of CSI configurations and triggered sub-configurations. A wireless communication method (400) for reporting CSI, when executed by a user equipment, UE, (110) selectively transmits (416) a modified CSI report to a network entity, NE, (120) based on the received one or more channel measurement resources, CMR, and the triggered CSI sub-configuration. An NE (120) receiving the modified CSI report transmits to the UE a CSI report configuration comprising a plurality of CSI sub-configurations, each CSI sub-configuration being associated with one or more CMRs or one or more CMRs and one or more interference measurement resources IMRs.

Inventors

  • ZHANG YUSHU

Assignees

  • 谷歌有限责任公司

Dates

Publication Date
20260512
Application Date
20230928

Claims (16)

  1. 1. A wireless communication method (400) performed by a user equipment, UE, (110) for reporting channel state information, CSI, the method comprising: receiving (404) a CSI report configuration comprising a plurality of CSI sub-configurations from a network entity NE (120), each CSI sub-configuration of the plurality of CSI sub-configurations being associated with at least one channel measurement resource CMR; receiving (408) one or more CMRs for a subset of the CSI sub-configurations prior to receiving CSI reference resources, and A CSI report is selectively transmitted (416) to the NE (120) based on the one or more CMRs and the triggered CSI-sub configuration.
  2. 2. The method of claim 1, wherein each CSI-sub-configuration of the plurality of CSI-sub-configurations is further associated with at least one interference measurement resource, IMR, wherein the receiving comprises receiving the one or more CMRs and the one or more IMRs for the subset of CSI-sub-configurations prior to receiving the CSI reference resource, and wherein the selectively transmitting is further based on the received one or more IMRs.
  3. 3. The method of any of claims 1 or 2, wherein the selectively transmitting comprises refraining from transmitting the CSI report unless the UE receives the one or more CMRs or the one or more CMRs and IMRs for each CSI-sub-configuration of the CSI configuration.
  4. 4. The method of any of claims 1 or 2, wherein the selectively transmitting comprises transmitting a modified CSI report when the UE receives the one or more CMRs or the one or more CMRs and IMRs for the triggered CSI-sub-configuration of the CSI configuration, and the modified CSI report comprises information associated with the triggered CSI-sub-configuration.
  5. 5. The method of any of claims 1 or 2, wherein the selectively transmitting comprises transmitting a modified CSI report when the UE receives the one or more CMRs or the one or more CMRs and IMRs for the subset of CSI-sub-configurations of the CSI configuration, and the modified CSI report comprises information associated with only the subset of the CSI-sub-configurations.
  6. 6. The method of any of claims 1 or 2, wherein the selectively transmitting comprises transmitting a modified CSI report when the UE receives the one or more CMRs or the one or more CMRs and IMRs for each of the subset of CSI-sub-configurations, and the modified CSI report comprises up-to-date measured information associated with the subset of CSI-sub-configurations and outdated information associated with the remaining CSI-sub-configurations.
  7. 7. The method of any of claims 1 or 2, wherein the selectively transmitting comprises transmitting a modified CSI report when the UE receives the one or more CMRs or the one or more CMRs and IMRs for the subset of CSI-sub-configurations, and the modified CSI report comprises outdated information associated with the subset of CSI-sub-configurations and outdated information associated with the remaining CSI-sub-configurations.
  8. 8. The method of any of claims 1 or 2, wherein the selectively transmitting comprises transmitting CSI reports with variable granularity such that the CSI reports do not include CSI information, include CSI information associated with only the subset of CSI-sub-configurations, or include CSI information associated with only triggered CSI-sub-configurations, and wherein the CSI information is one or more of up-to-date measured information and outdated measured information.
  9. 9. The method of any one of claims 1 to 8, wherein the one or more CMRs are received during an active time of at least one of cell discontinuous transmission, DTX, or UE discontinuous reception, DRX.
  10. 10. The method of any one of claims 1 to 9, further comprising: The number of CSI processing units is determined based on at least one of: The number of triggered CSI-sub-configurations with the one or more CMRs received prior to the CSI reference resource, The number of triggered CSI-sub configurations, or A weighted sum of the triggered CSI-sub-configurations, wherein the weights are related to the latest measured CSI or outdated measured CSI associated with the triggered CSI-sub-configurations.
  11. 11. The method of any of claims 2 to 10, wherein the list of CSI reference signal, CSI-RS, resource indices for the one or more CMRs is mapped one-to-one to the list of CSI-RS resource indices for the one or more IMRs.
  12. 12. The method of any one of claims 1 to 11, further comprising: Reporting UE capabilities indicating supported CSI reporting schemes for the CSI reporting to the NE based on receipt of the one or more CMRs for the subset of the CSI sub-configurations.
  13. 13. The method of any one of claims 1 to 12, further comprising: defining a plurality of power offsets, one power offset being related to an energy per resource element EPRE ratio between a downlink communication channel PDSCH and a channel state information resource signal CSI-RS for interference measurement, and Downlink communication channel interference is calculated based on the one power offset for the interference measurement.
  14. 14. A wireless communication method (500) performed by a network entity, NE, (120) for receiving channel state information, CSI, the method comprising: Transmitting (504) to the user equipment, UE, (110) a CSI report configuration comprising a plurality of CSI sub-configurations, each CSI sub-configuration being associated with at least one channel measurement resource, CMR, or at least one channel measurement resource, CMR, and at least one interference measurement resource, IMR; transmitting (508) one or more CMRs or one or more CMRs and IMRs for a subset of the CSI sub-configurations prior to transmitting CSI reference resources, and A CSI report is received (516) from the UE (110), the CSI report including information determined based on one or more CMRs or one or more CMRs and IMRs received by the UE and the triggered CSI-sub configuration.
  15. 15. The method of claim 14, wherein the one or more CMRs or the one or more CMRs and IMR transmit during an active time of at least one of cell discontinuous transmission, DTX, or UE discontinuous reception, DRX.
  16. 16. A wireless communication device (210, 220) comprising a transceiver (213, 222), a processor (216, 223), and a computer-readable storage medium (217, 224) storing executable instructions for causing the processor to perform any of the methods of claims 1-14 using the transceiver.

Description

Method for channel state information measurement and reporting for multiple CSI sub-configurations for network power saving Technical Field This document generally describes methods and apparatus that operate in a wireless communication system, such as, but not limited to, those described in the 5G standard document, referred to as a 3 rd generation partnership project (3 GPP) communication system. Background In wireless communication, channel State Information (CSI) refers to information regarding the current state of a wireless communication channel between a transmitter (e.g., a base station) and a receiver (e.g., a User Equipment (UE)). CSI characterizes the behavior of a wireless channel by including factors such as signal strength, signal-to-noise ratio, fading, interference, and the like. CSI may be used by Network Entities (NEs) for resource allocation, beamforming, optimizing multiple-input multiple-output (MIMO) configuration, interference mitigation, adaptive modulation and coding, handover and mobility management, resource scheduling, and so on. CSI may be estimated/measured by the UE after comparing (1) a known CSI reference signal (CSI-RS) that is a particular resource transmitted by the NE and used to measure and report channel conditions between the UE and the NE, and (2) a corresponding measured signal. The term NE indicates a Base Station (BS), a distributed unit of a distributed BS, or another network device of a Radio Access Network (RAN) that communicates with UEs. Conventionally, for MIMO systems, CSI may provide the NE with the necessary information for selecting a digital precoder for the UE. The NE may configure CSI reporting by using Radio Resource Control (RRC) signaling (e.g., CSI-ReportConfig), where CSI-RS is used as Channel Measurement Resources (CMR) for the UE to measure downlink channels and turn off some antenna elements to achieve Network Energy Savings (NEs). In addition to the CMR, the NE may also configure Interference Measurement Resources (IMR) to enable the UE to measure channel interference. CMR is a specific part of network resources, including time slots, frequency bands or physical resources (such as antennas) allocated for making channel measurements. These resources are reserved to ensure that measurement tasks do not interfere with conventional data transmission activities. Based on the configured CMR and IMR, the UE is able to report CSI, which may include at least one of a Rank Indicator (RI), a Precoder Matrix Indicator (PMI), a Channel Quality Indicator (CQI), and a Layer Indicator (LI). The RI and PMI characterize the digital precoder, the CQI indication is used to assist the NE in determining the signal-to-interference-plus-noise (SINR) state of the Modulation and Coding Scheme (MCS), and the LI indicates the strongest layer of the precoder indicated by the RI and PMI. The NE may trigger the UE to provide CSI reports based on the configured CMR or CMR and IMR before sending CSI reference resources to the UE. The CSI reference resource may be located in a time slot before the CSI reporting time slot. CSI reference resources are defined, for example, in 3GPP technical specification TS 38.214. After a specific event occurs in the network, such as CSI reporting (reconfiguration), serving cell activation, bandwidth part (BWP) change or activation of semi-persistent CSI (SP-CSI), the UE reports the CSI report only after receiving at least one CSI-RS transmission occasion for channel measurement or at least one CSI-RS transmission occasion for channel measurement and one interference measurement CSI-RS CSI-IM occasion for interference measurement no later than the CSI reference resource, otherwise the UE discards the report. However, when (1) the CSI configuration comprises a plurality of CSI-sub-configurations, and (2) the UE receives at least one of a transmission occasion for CMR or a transmission occasion for CMR and IMR for only some (or a subset) of the CSI-sub-configurations, the current 5G rule for transmitting CSI reports to the NE is undefined. For example, to achieve Network Energy Savings (NES), the NE may configure N in a CSI reporting configuration (e.g.) The CSI-sub-configurations, and the NE may trigger (i.e., instruct or request) the UE to report M (e.g.) And (3) the CSI. In other words, the NE may require the UE to report CSI for a subset of all CSI-sub-configurations for a given CSI reporting configuration. In each CSI sub-configuration, the NE may configure a list of CSI-RS resource indices for channel measurements (e.g., CMR). The NE may transmit CSI-RS under different CSI-sub configurations based on different antenna elements with different beams. Then, based on the UE report, the NE may select the correct antenna elements for downlink transmission and turn off some of the antenna elements to implement NEs. As shown in fig. 1, which is a timing diagram indicating signals received by a UE, when the UE partially receives (1) CSI-RS transmis