R1-2600144
discussion
Synchronization acquisition and beam measurement for 6GR
From Huawei
Summary
This document from Huawei (R1-2600144) presents 30 proposals and 17 observations on 6GR physical layer design for initial access, paging, and mobility, focusing heavily on coverage enhancement, network energy saving, and system simplification.
Position
Huawei proposes studying a new SSB pattern with increased frequency-domain and time-domain resources, designed assuming 5MHz with 15kHz SCS, to improve single-shot detection performance over NR. They propose studying an extended always-on signal periodicity of 160ms combined with clustered transmission to achieve NES gains of 23% and 17% for CAT1 and CAT2+ BSs respectively, while acknowledging this creates uneven synchronization and measurement opportunity distribution requiring mitigation via additional synchronization signals (AD-SS) in LP mode and sparse sync raster design. They propose studying configurable SIB1 PDCCH/PDSCH bandwidth larger than 48RBs, multi-slot SIB1 PDSCH with DMRS bundling, cross-beam combination for SIB1 PDCCH/PDSCH, and orthogonal DMRS design for multi-cell interference suppression. They support on-demand SIB1 via UL-WUS in standalone deployment and propose studying simplified sequence-based paging with large pool size to replace subgroup-based paging, reducing false wake-up and latency. They propose studying a unified beam reporting and CSI acquisition framework harmonizing MIMO and mobility configurations, and studying AI/ML-based temporal beam prediction for initial access.
Key proposals
- Proposal 1 (Sec 2.1): The coverage evaluation results achieved in agenda 10.5.0 are used to guide 6GR physical channels/signals design during initial access and random access.
- Proposal 3 (Sec 2.2): Study a unified initial access framework based on a single set of common signals and channels, while allowing a configurable bandwidth for at least some of the signals and channels during initial access.
- Proposal 4 (Sec 3.1): Study a new SSB pattern with improved single-shot detection performance than NR with increased number of frequency-domain and time-domain resources.
- Proposal 6 (Sec 3.2): Study extending the number of SSBs within an SSB burst set by supporting narrower SSB beams and/or SSB beam repetition(s), and clustered transmission within a SSB burst set.
- Proposal 7 (Sec 3.3): Study an extended periodicity of 160ms for common always-on signals with clustered transmissions for initial access under TN.
- Proposal 8 (Sec 3.4/3.5): Study methods to mitigate the impact of extending the periodicity of common signals on UE performance by considering sparse sync raster and additional sync signal.
- Proposal 10 (Sec 3.5): Support additional synchronization signal to have a balance between network energy saving and UE performance.
- Proposal 11 (Sec 4.1): Study configurable bandwidth of SIB1 PDCCH/PDSCH larger than 48RBs and the potential impacts to UE.
- Proposal 15 (Sec 4.2): Study multi-slot SIB1 PDSCH transmission schemes and DMRS bundling across slots.
- Proposal 19 (Sec 4.2): Study FDMed SIB1 transmission for network energy saving.
- Proposal 20 (Sec 4.3): Study UL-WUS and the corresponding procedure for requesting OD-SIB1 in standalone deployment.
- Proposal 21 (Sec 5.1): Study simplified paging to achieve low latency and low false UE wake-up of improved energy efficiency in 6G RRC_IDLE state, where UE can maintain a UE dedicated connection ID.
- Proposal 23 (Sec 5.2): Study the clustered POs distribution for network energy saving.
- Proposal 26 (Sec 6.1): Study a unified beam reporting framework, including configuration, measurement and reporting aspects, for MIMO and mobility.
- Proposal 30 (Sec 6.3): Study AI/ML based beam prediction for initial access, such as temporal domain prediction.