Nokia · 10.6.1.1

Nokia proposes that RAN1 should assume a residual CFO of 2 ppm for the EE processing state rather than the previously agreed 5 ppm, arguing this benefits WUS signal design. They require RAN1 to explore sequence families beyond Zadoff-Chu, specifically m-sequence and Gold sequence, and evaluate them using auto-correlation peak prominence, cross-correlation, and receiver complexity as KPIs. They propose studying both subgroup-specific sequence mapping and segmented bitmap mapping schemes, with the design controlled by the number of segments to mimic either approach. For coverage, they require that WUS match paging PDCCH coverage (AL8 and AL16) in RRC IDLE mode and extend the same target to RRC CONN mode, citing the ability to use more receive chains.

Nokia proposes assuming a more stringent residual CFO of 1 ppm for the EE processing state, arguing that SSB-based calibration during active states can maintain this accuracy from initial cell search. They require the minimum number of RX chains for 6G WUS reception to depend on RRC state and frequency range, noting that deep/ultra-deep sleep states justify single RX chain operation due to lack of channel state information and CFO accuracy. Nokia proposes exploring m-sequence and Gold sequence families as alternatives to Zadoff-Chu for 6G WUS, while requiring evaluation of sequences based on auto correlation peak prominence, low cross correlation performance, and receiver complexity. They propose studying both direct subgroup-specific sequence mapping (codepoint scheme) and segmented bitmap mapping to OFDM sequences, noting that controlling the number of segments allows the design to mimic either scheme. Nokia also proposes striving for WUS coverage equivalent to paging PDCCH coverage at aggregation levels 8 and 16.