R1-2601881
discussion
Other aspects for MIMO operation
From TCL
Summary
This TCL contribution proposes two study areas for 6G MIMO operation: enhancing Tracking Reference Signal (TRS) time-domain flexibility beyond 5G NR's on-demand principle, and investigating the impact of SRS insertion loss imbalance and UE Rx imbalance on channel reciprocity in TDD systems for joint DL/UL CSI acquisition.
Position
TCL argues that 5G NR TRS periodic configuration lacks sufficient flexibility for energy saving, and proposes studying flexible time-domain behavior including trigger mechanisms and periodic adaptation. They identify non-reciprocal insertion loss at the UE RF link as a critical factor breaking TDD channel reciprocity, and propose studying the performance impact of SRS insertion loss imbalance on reciprocity. They additionally propose studying Rx imbalance among different Rx antennas for joint DL and UL CSI acquisition.
Key proposals
- Proposal 1 (Sec 2.1): For TRS configuration, 6G should consider further studying flexible time-domain behavior, such as trigger methods, periodic adaptation, and other related aspects.
- Proposal 2 (Sec 2.2): For CSI acquisition and report by joint DL and UL, support to study performance impact of SRS IL imbalance on reciprocity in TDD and the impact of Rx imbalance among different Rx antennas.