US-20260128773-A1 - CODEBOOK-BASED PRECODING BASED ON SRS PORT GROUPING

Abstract

A Wireless Transmit/Receive Unit (WTRU) comprises a processor configured to send a report indicating sounding reference signal (SRS) port grouping capability of the WTRU. The processor is further configured to receive an indication of at least a first SRS port group and a second SRS port group, where each of the first and second SRS port groups is associated with a respective subset of antenna ports. The processor is further configured to estimate a first channel state information (CSI) for the first SRS port group and a second CSI for the second SRS port group, send one or more CSI reports indicating the first estimated CSI and the second estimated CSI, and receive configuration information indicating a codeword (CW) for processing a scheduled transmission using antenna ports of at least one of the first SRS port group or the second SRS port group.

Inventors

• Omid Saatlou
• Afshin Haghighat
• Jonghyun Park
• Mohammad Irfan
• Loic Canonne-Velasquez
• Virgil Comsa
• Moon Il Lee

Assignees

• INTERDIGITAL PATENT HOLDINGS, INC.

Dates

Publication Date

20260507

Application Date

20241104

Claims (20)

1. 1 . A wireless transmit/receive unit (WTRU) comprising: a processor configured to: send a report indicating sounding reference signal (SRS) port grouping capability of the WTRU; receive an indication of at least a first SRS port group and a second SRS port group, wherein each of the first SRS port group and the second SRS port group is associated with a respective subset of antenna ports; estimate a first channel state information (CSI) for the first SRS port group and a second CSI for the second SRS port group; send one or more CSI reports indicating the first estimated CSI and the second estimated CSI; and receive configuration information indicating a codeword (CW) for processing a scheduled transmission using antenna ports of at least one of the first SRS port group or the second SRS port group.
2. 2 . The WTRU of claim 1 , wherein the processor is further configured to: receive an indication to trigger CSI reporting; and estimate the first CSI and the second CSI in response to receiving the indication to trigger CSI reporting.
3. 3 . The WTRU of claim 1 , wherein the processor is further configured to: estimate the first CSI and the second CSI according to a first estimation mode and a second estimation mode; and send the one or more CSI reports to indicate, for each of the first estimation mode and the second estimation mode, the first CSI and the second CSI.
4. 4 . The WTRU of claim 3 , wherein the processor, to estimate the first CSI and the second CSI in the first estimation mode, is further configured to: determine the first CSI based on a measurement performed on a first subset of the antenna ports corresponding to the first SRS port group; and determine the second CSI based on a measurement performed on a second subset of the antenna ports corresponding to the second SRS port group, and wherein the processor, to estimate the first CSI and the second CSI in the second estimate mode, is further configured to: determine the first CSI and the second CSI based on a joint measurement performed on the antenna ports corresponding to both of the first SRS port group and the second SRS port group.
5. 5 . (canceled)
6. 6 . The WTRU of claim 3 , wherein the processor, to send the one or more CSI reports, is further configured to: receive an indication to trigger CSI reporting and a priority for CSI reporting associated with each of the first SRS port group and the second SRS port group; and based on the first SRS port group having a higher priority than the second SRS port group, send a first CSI report corresponding to the first SRS port group prior to a second CSI report corresponding to the second SRS port group.
7. 7 . The WTRU of claim 1 , wherein the processor is further configured to: based on the report indicating that the WTRU supports a plurality of port grouping configurations, receive an indication of a recommended port grouping configuration; and based on the recommended port grouping configuration, select the first SRS port group and the second SRS port group and the respective subset of the antenna ports of each of the first SRS port group and the second SRS port group.
8. 8 . The WTRU of claim 1 , wherein the processor is further configured to: based on the received indication of the first SRS port group and the second SRS port group, determine the respective subsets of the antenna ports assigned to each of the first SRS port group and the second SRS port group.
9. 9 . The WTRU of claim 1 , wherein the processor is further configured to: receive, via radio resource control (RRC), the indication of the first SRS port group and the second SRS port group.
10. 10 . The WTRU of claim 1 , wherein the first CSI and the second CSI include at least one of a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a layer indicator (LI).
11. 11 . A method performed by a wireless transmit/receive unit (WTRU), the method comprising: sending a report indicating sounding reference signal (SRS) port grouping capability of the WTRU; receiving an indication of at least a first SRS port group and a second SRS port group, wherein each of the first SRS port group and the second SRS port group is associated with a respective subset of antenna ports; estimating a first channel state information (CSI) for the first SRS port group and a second CSI for the second SRS port group; sending one or more CSI reports indicating the first estimated CSI and the second estimated CSI; and receiving configuration information indicating a codeword (CW) for processing a scheduled transmission using antenna ports of at least one of the first SRS port group or the second SRS port group.
12. 12 . The method of claim 11 , further comprising: receiving an indication to trigger CSI reporting; and estimating the first CSI and the second CSI in response to receiving the indication to trigger CSI reporting.
13. 13 . The method of claim 11 , further comprising: estimating the first CSI and the second CSI according to a first estimation mode and a second estimation mode; and sending the one or more CSI reports to indicate, for each of the first estimation mode and the second estimation mode, the first CSI and the second CSI.
14. 14 . The method of claim 13 , wherein estimating the first CSI and the second CSI in the first estimation mode comprises: determining the first CSI based on a measurement performed on a first subset of the antenna ports corresponding to the first SRS port group; and determining the second CSI based on a measurement performed on a second subset of the antenna ports corresponding to the second SRS port group, wherein estimating the first CSI and the second CSI in the second estimation mode comprises determining the first CSI and the second CSI based on a joint measurement performed on the antenna ports corresponding to both of the first SRS port group and the second SRS port group.
15. 15 . (canceled)
16. 16 . The method of claim 13 , wherein sending the one or more CSI reports comprises: receiving an indication to trigger CSI reporting and a priority for CSI reporting associated with each of the first SRS port group and the second SRS port group; and based on the first SRS port group having a higher priority than the second SRS port group, sending a first CSI report corresponding to the first SRS port group prior to a second CSI report corresponding to the second SRS port group.
17. 17 . The method of claim 11 , further comprising: based on the report indicating that the WTRU supports a plurality of port grouping configurations, receiving an indication of a recommended port grouping configuration; and based on the recommended port grouping configuration, selecting the first SRS port group and the second SRS port group and the respective subset of the antenna ports of each of the first SRS port group and the second SRS port group.
18. 18 . The method of claim 11 , further comprising: based on the received indication of the first SRS port group and the second SRS port group, determine the respective subsets of the antenna ports assigned to each of the first SRS port group and the second SRS port group.
19. 19 . The method of claim 11 , further comprising: receiving, via radio resource control (RRC), the indication of the first SRS port group and the second SRS port group.
20. 20 . The method of claim 11 , wherein the first CSI and the second CSI include at least one of a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a layer indicator (LI).

Description

BACKGROUND When a network operates in a time division duplex (TDD) mode (e.g., when there is reciprocity between uplink (UL) and downlink (DL) channels), a gNB can calculate DL precoding weights based on a sounding reference signal (SRS) that a user transmits in the UL channel. SUMMARY An example Wireless Transmit/Receive Unit (WTRU) comprising a processor is described. The processor is configured to send a report indicating sounding reference signal (SRS) port grouping capability of the WTRU. The processor is further configured to receive an indication of at least a first SRS port group and a second SRS port group, where each of the first and second SRS port groups is associated with a respective subset of antenna ports. The processor is further configured to estimate a first channel state information (CSI) for the first SRS port group and a second CSI for the second SRS port group. The processor is further configured to send one or more CSI reports indicating the first estimated CSI and the second estimated CSI. The processor is further configured to receive configuration information indicating a codeword (CW) for processing a scheduled transmission using antenna ports of at least one of the first SRS port group or the second SRS port group. In examples, the processor is further configured to receive an indication to trigger CSI reporting. In examples, the processor is further configured to estimate the first CSI and the second CSI in response to receiving the indication to trigger CSI reporting. In examples, the processor is further configured to estimate the first CSI and the CSI according to a first estimation mode and a second estimation mode. In examples, the processor is further configured to send the one or more CSI reports to indicate, for each of the first and second estimation modes, the first and second CSIs. In examples, the processor, to estimate the first CSI and the second CSI in the first estimation mode, is further configured to determine the first CSI based on a measurement performed on a first subset of the antenna ports corresponding to the first SRS port group. In examples, the processor, to estimate the first CSI and the second CSI in the first estimation mode, is further configured to determine the second CSI based on a measurement performed on a second subset of the antenna ports corresponding to the second SRS port group. In examples, the processor, to send the one or more CSI reports, is further configured to receive an indication to trigger CSI reporting and a priority for CSI reporting associated with each of the first and second SRS port groups. In examples, the processor, to send the one or more CSI reports, is further configured to send a first CSI report corresponding to the first SRS port group prior to a second CSI report corresponding to the second SRS port group based on the first SRS port group having a higher priority than the second SRS port group. In examples, the processor is further configured to receive an indication of a recommended port grouping configuration based on the report indicating that the WTRU supports a plurality of port grouping configurations. In examples, the processor is further configured to select the first and second SRS port groups and the respective subset of the antenna ports of each of the first and second SRS port groups based on the recommended port grouping configuration. In examples, the processor is further configured to determine the respective subsets of the antenna ports assigned to each of the first and second SRS port groups based on the received indication of the first and second SRS port groups. In examples, the processor is further configured to receive, via radio resource control (RRC), the indication of the first and second SRS port groups. In examples, the first and second CSIs include at least one of a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a lawful interception (LI). An example method performed by a WTRU is described. The method comprises sending a report indicating SRS port grouping capability of the WTRU. The method further comprises receiving an indication of at least a first SRS port group and a second SRS port group, where each of the first and second SRS port groups is associated with a respective subset of antenna ports. The method further comprises estimating a first CSI for the first SRS port group and a second CSI for the second SRS port group. The method further comprises sending one or more CSI reports indicating the first estimated CSI and the second estimated CSI. The method further comprises receiving configuration information indicating a CW for processing a scheduled transmission using antenna ports of at least one of the first SRS port group or the second SRS port group. In examples, the method further comprises receiving an indication to trigger CSI reporting. In examples, the method further comprises estimating the first CSI and the second CSI in