R1-2600118
discussion
Discussion on beam management for downlink and uplink for 6GR
From Spreadtrum
Summary
This Spreadtrum contribution to 3GPP RAN1#124 discusses beam management for 6G Radio, presenting 2 observations on NR beam management effectiveness and standardization complexity, along with 11 proposals covering beamforming architecture, unified CSI frameworks, AI/ML-based beam management, and collaborative UE schemes.
Position
Spreadtrum proposes hybrid beamforming as the fundamental beamforming architecture for 6G ultra large antenna arrays, supporting digital, analog, and hybrid architectures. They propose studying a unified CSI framework that integrates beam management across network-controlled and UE-initiated cases, single TRP and multi-TRP, and intra-cell and inter-cell scenarios, including LTM. They require studying beam measurement schemes with low latency and overhead, and consider designing a unified event-triggered reporting procedure covering BFR, UE-initiated beam management, and event-triggered TRP/cell switching. They support carrying forward NR BM-Case1 (spatial domain DL Tx beam prediction) and BM-Case2 (temporal DL Tx beam prediction) into 6G, and extending AI/ML beam prediction to inter-cell/multi-TRP and cross-frequency scenarios in 6G Day1. They consider NR's unified TCI framework as the baseline for 6G TCI framework and propose studying collaborative beam measurement and reporting based on UE aggregation to reduce overall overhead and power consumption.
Key proposals
- Proposal 1 (Sec 2.1): For 6G system, the hybrid beamforming can be the fundamental beamforming architecture.
- Proposal 3 (Sec 2.2): Study a unified CSI framework to integrate beam management for different cases, e.g. network-controlled and UE initiated, single TRP and multi-TRP, intra-cell and inter-cell.
- Proposal 4 (Sec 2.3): Study beam measurement scheme with low latency and overhead in 6G.
- Proposal 5 (Sec 2.3): Consider a simple and unified event triggered reporting procedure, e.g. BFR, UE initiated beam management, event triggered TRP/cell switching.
- Proposal 6 (Sec 2.3): Consider to design a unified and flexible beam reporting to accommodate different scenarios, e.g. inter-cell, multi-TRP, UL beam selection.
- Proposal 7 (Sec 2.3): NR unified TCI framework can be the baseline for 6G TCI framework.
- Proposal 8 (Sec 2.3): Study enhancing beam indication scheme to support different scenarios.
- Proposal 9 (Sec 2.3): Study collaborative beam measurement and reporting based on UE aggregation.
- Proposal 10 (Sec 2.3.1): Support the use cases of AI/ML based beam management specified in NR included in 6G, i.e. BM-Case1 and BM-Case2.
- Proposal 11 (Sec 2.3.1): Support inter-cell/multi-TRP DL Tx beam prediction and cross frequency DL Tx beam prediction in 6G Day1.
- Proposal 2 (Sec 2.1): The beam measurement procedures in NR can be a starting point in 6G, e.g. downlink P1/P2/P3 and uplink U1/U2/U3 procedures.