R1-2600125
discussion
Discussion on design of WUS with OFDM based sequence for 6GR
From Spreadtrum
Summary
This document from Spreadtrum/UNISOC presents 8 proposals and 1 observation on the design of 6G DL Wake-Up Signal (WUS) with OFDM-based sequences, covering basic principles, coverage, waveform, synchronization, sequence design, and receiver processing.
Position
Spreadtrum/UNISOC proposes using 5G Rel-19 LP-WUS functionality (subgroup paging indication, PDCCH monitoring indication, serving cell measurement) as the baseline for 6G DL WUS with OFDM-based sequence. They require a single unified WUS solution for all device types and require cell-wise coverage to achieve complete UE power saving gain, with Msg3 coverage as the starting point. They propose studying CP-OFDM as the waveform, arguing no distinct power consumption difference versus DFT-S-OFDM when considering FFT-based correlation and noting CP-OFDM simplifies operation when WUS is FDMed with other CP-OFDM signals. They propose studying both 6G SSB reuse and dedicated LP-SS for synchronization, and propose evaluating Gold, M, and ZC sequences with a payload of at least 5 bits, while arguing that WUS reliability targets for miss detection and false alarm rates require dedicated study due to potential low-precision hardware and synchronization errors in EE processing state.
Key proposals
- Proposal 1 (Sec 2.1): The functions of 5G LP-WUS can be starting point of 6G DL WUS with OFDM based sequence, i.e., subgroup indication for paging, indication on PDCCH monitoring, measurement on serving cell.
- Proposal 2 (Sec 2.1): Strive DL WUS with OFDM based sequence apply for all device types and purse one unified solution.
- Observation 1 (Sec 2.2): In 6GR, DL WUS should be strived to support cell-wise coverage to achieve complete UE power saving gain.
- Proposal 3 (Sec 2.2): For the coverage target of DL WUS with OFDM based sequence, the coverage of Msg3 can be starting point. Higher coverage target can be considered if needed.
- Proposal 4 (Sec 2.3): Study and evaluate DL WUS with OFDM based sequence with CP-OFDM waveform.
- Proposal 5 (Sec 2.4): Following options can be studied for synchronization in EE processing state: Option 1: Reuse 6G sync signals; Option 2: Dedicated LP-SS.
- Proposal 6 (Sec 2.5): Gold sequence, M sequence, and ZC sequence can be considered for the evaluation on DL WUS with OFDM based sequence.
- Proposal 7 (Sec 2.5): The information carried by DL WUS with OFDM based sequence is at least 5 bits.
- Proposal 8 (Sec 2.6): The target miss detection rate and false alarm rate of WUS should be determined in study item.