R1-2509143
discussion
Waveform for 6GR air interface
From MediaTek
Summary
This document contributes two proposals for 6G uplink waveform enhancements using DFT-s-OFDM, focusing on cell edge coverage and throughput. It introduces an O-QAM precoder and subcarrier truncation techniques, evaluating them using the newly agreed 'Net Gain' performance metric and demonstrating significant gains of 2dB and 6.9dB over their respective references.
Position
MediaTek proposes the O-QPSK modulated DFT-s-OFDM waveform for 6G uplink, demonstrating it provides a 2dB net gain over π/2-BPSK for coverage enhancement. They present a technical case for using an O-QAM precoder, which utilizes a (2,1) repetition code instead of 2-times up-sampling, to achieve significant PAPR reduction. For throughput enhancement at higher spectral efficiencies, they propose supporting O-QPSK with subcarrier truncation, exploiting frequency-domain symbol redundancy to achieve a 6.9 dB net gain over QPSK modulated DFT-s-OFDM. They base their evaluation on the agreed 'Net Gain' performance metric using a 3GPP polynomial PA model and ACLR requirements derived from 5G NR guard-band bandwidths.
Key proposals
- Proposal 1 (Sec 2.1): As O-QPSK modulated DFT-s-OFDM offers a significant net gain of 2dB with respect to π/2-BPSK modulated DFT-s-OFDM, support O-QPSK modulated DFT-s-OFDM for 6G UL coverage enhancement.
- Proposal 2 (Sec 2.2): Support O-QPSK modulated DFT-s-OFDM with subcarrier truncation for coverage enhancement at spectral efficiency larger than 1 bit/s/Hz.