R1-2509112
discussion
Considerations of 6GR Channel Coding
From Apple
Summary
This document from Apple presents 16 proposals and 5 observations addressing 6G channel coding across both control and data channels, focusing on enhanced FAR evaluation, scalable polar coding with segmentation and inter-segment coding, and new LDPC base graphs optimized for high throughput and low power.
Position
Apple proposes adjusting FAR requirements on a per-category basis and incorporating both operating SNR and path-metric-assisted early termination into standardized evaluation assumptions. They propose simplifying CRC precoding for PDCCH configurations beyond the 5G NR range using a segmented CRC method with intermediate checkpoints to enhance CRC-assisted early termination. For scalability, they propose studying backward-compatible polar coding segmentation combined with the Partially Polarized Polar (PPP) inter-segment coding scheme to recover coding gain while enabling two-stage DCI decoding for reduced UE complexity. For data channels, they propose new LDPC base graphs optimized for small-iteration performance with incremental redundancy supporting a range of high code rates, increased maximum lifting size up to 1024, packet-level coding across code blocks, and compact base graphs for low-power use cases. They present technical analysis showing SNR-to-spectral-efficiency translation and provide detailed DCI payload size estimates demonstrating the need to exceed the 140-bit 5G NR limit in 6G.
Key proposals
- Proposal 1 (Sec 2.1): It is proposed to adjust the FAR requirements on a per-category basis and to study and define all FAR categories under consistent evaluation assumptions as part of the transition to 6G.
- Proposal 6 (Sec 2.1): It is proposed to simplify the CRC precoding for PDCCH configurations beyond the 5G NR range in order to enhance CRC-assisted early termination while maintaining compliance with all FAR category requirements.
- Proposal 7 (Sec 2.1): It is proposed for 6G to study scalable and backward-compatible polar coding solutions such as segmentation to support increased control payload sizes without imposing significant complexity or implementation burden on either the UE or the network operators.
- Proposal 10 (Sec 2.1): It is proposed for 6G to combine inter-segment coding schemes, such as the Partially Polarized Polar (PPP) approach, with DCI segmentation to recover coding gain and further reduce the decoding complexity of the primary segments in PDCCH.
- Proposal 11 (Sec 2.1): It is proposed to investigate the use of dynamic frozen bits in the design of polar codes beyond 5G NR range, to further enhance performance of control channel codes.
- Proposal 12 (Sec 2.2.3): It is proposed to consider new LDPC base graph design to support high throughput use cases by optimizing the performance in the small number of iterations, without losing performance in the large number of iterations compared to 5G NR.
- Proposal 13 (Sec 2.2.3): It is proposed to support high-throughput use cases by enabling a range of high code rates with the incremental redundancy code, rather than limiting the design to a single code rate.
- Proposal 14 (Sec 2.2.3): It is proposed to consider supporting high throughput use cases by increasing the maximum lifting size up to 1024.
- Proposal 15 (Sec 2.2.4): It is proposed to consider packet level coding of code blocks to improve both retransmission rate and spectral efficiency.
- Proposal 16 (Sec 2.2.5): It is proposed to support new base graph designs with compact sizes to better address low-power use cases.
- Proposal 5 (Sec 2.1): It is proposed to study and define a standardized early-termination scheme as part of the PDCCH decoder assumptions, with the objective of relaxing processing constraints for both UEs and network operators as 6G evolves.
- Proposal 4 (Sec 2.1): It is proposed to include path-metric-assisted early termination as part of the PDCCH decoder assumptions used for BLER evaluation.
- Proposal 8 (Sec 2.1): It is proposed for 6G to study efficient segmentation strategies for PUCCH that minimize BLER degradation.
- Proposal 9 (Sec 2.1): It is proposed for 6G to study efficient segmentation strategies for PDCCH that leverage two-stage DCI decoding to minimize power consumption and clock-cycle usage in the UE.