面向6G的新型多址与波形技术

doi:10.11959/j.issn.1000-0801.2022271

电信科学 ›› 2022, Vol. 38 ›› Issue (10): 36-45.doi: 10.11959/j.issn.1000-0801.2022271

• 专题：6G无线传输技术 • 上一篇下一篇

面向6G的新型多址与波形技术

李华, 郝诗雅, 巩彩红, 李倩倩, 戴晓明

北京科技大学计算机与通信工程学院，北京 100083

修回日期:2022-10-11 出版日期:2022-10-20 发布日期:2022-10-01
作者简介:李华（1995- ），男，北京科技大学计算机与通信工程学院博士生，主要研究方向为5G+/6G、非正交多址接入、正交时频空调制技术和大规模MIMO信号检测与信道估计
郝诗雅（1995- ），女，北京科技大学计算机与通信工程学院博士生，主要研究方向为5G+/6G、非正交多址接入、正交时频空调制技术和大规模MIMO信号检测
巩彩红（1988- ），女，北京科技大学计算机与通信工程学院博士生，主要研究方向为物理层安全、非正交多址接入技术和智能超表面
李倩倩（1993- ），女，北京科技大学计算机与通信工程学院博士生，主要研究方向为非正交多址接入技术、智能超表面技术和信号检测与估计
戴晓明（1973- ），男，博士，北京科技大学计算机与通信工程学院教授、博士生导师，图样分割多址技术提出者，IMT-2020（5G）新型多址接入技术组副组长，主要研究方向为5G+/6G、大规模MIMO天线、非正交多址接入和ASIC芯片设计等
基金资助:
国家自然科学基金资助项目(61871029)

New multiple access and waveform technology for 6G

Hua LI, Shiya HAO, Caihong GONG, Qianqian LI, Xiaoming DAI

School of Computer and Communication Engineering, University of Science and Technology Beijing, Beijing 100083, China

Revised:2022-10-11 Online:2022-10-20 Published:2022-10-01
Supported by:
The National Natural Science Foundation of China(61871029)

摘要/Abstract

摘要：

随着互联网终端海量接入，传统正交多址接入（orthogonal multiple access，OMA）技术接入效率低， 5G NR 系统面临拥塞及高时延问题，并且在高速场景下，基于正交频分复用（orthogonal frequency-division multiplexing，OFDM）的系统由于多普勒效应性能严重恶化。为满足6G在高速移动场景下低时延、高可靠、海量接入需求，首先，结合正交时频空间（orthogonal time frequency space，OTFS）和图样分割多址接入（pattern division multiple access，PDMA）技术，提出了一种OTFS-PDMA联合方案；然后，推导PDMA传输码字在时延-多普勒（delay-Doppler，DD）域采用不同分配方式的系统输入-输出关系；最后，提出了一种基于期望传播算法（expectation propagation algorithm，EPA）的低复杂度接收机。仿真结果表明，OTFS-PDMA较传统的OTFS-OMA技术能够显著提升误码率性能；对于规则码本，不同码字分配方案性能相似，而对于非规则码本，发送信号采用集中式扩频优于离散式扩频，且对于离散式扩频，PDMA 扩频信号沿多普勒轴分配，系统可取得较好性能；此外EPA接收机性能优于其他传统接收机。

关键词: 正交时频空间, 图样分割多址接入, 码字分配, 期望传播算法

Abstract:

With the explosive growth of Internet devices, the 5G new radio (NR) system faces congestion and high latency issues due to the low access efficiency of traditional orthogonal multiple access (OMA).Besides this, the performance of the orthogonal frequency-division multiplexing (OFDM)-based system is severely degraded due to the Doppler effect in high-speed scenarios.To meet the low-latency, high-reliability, and massive connection requirements of 6G communication in high-mobility scenarios, firstly, a novel orthogonal time frequency space (OTFS)-based pattern division multiple access (PDMA) scheme, shortened as OTFS-PDMA, was proposed.Then, the system input-output relationship of different types of PDMA codeword allocation schemes in the delay-Doppler (DD) domain was derived.Finally, a low-complexity expectation propagation algorithm (EPA)-based receiver was proposed.Simulation results illustrate that the proposed OTFS-PDMA scheme achieves significant performance gains over the conventional OTFS-OMA scheme.For regular PDMA patterns, the PDMA codeword allocation has a slight impact on the system performance.For irregular patterns, the centralized spreading method outperforms the discrete one.For discrete spreading scheme, the system can achieve better performance by assigning irregular PDMA spread signals along the Doppler direction.In addition, the proposed EPA receiver outperforms its conventional counterparts.

Key words: orthogonal time frequency space, pattern division multiple access, pattern allocation, expectation propagation algorithm

中图分类号:

TP393

李华, 郝诗雅, 巩彩红, 李倩倩, 戴晓明. 面向6G的新型多址与波形技术[J]. 电信科学, 2022, 38(10): 36-45.

Hua LI, Shiya HAO, Caihong GONG, Qianqian LI, Xiaoming DAI. New multiple access and waveform technology for 6G[J]. Telecommunications Science, 2022, 38(10): 36-45.

图/表 8

图1

图2

图3

图4

图5

表1

复杂度分析"

EPA模块	复杂度值
计算VN到FN均值方差	$6 K N_{s} L d_{v}$
计算FN到VN均值方差	$4 M N L d_{f}$
计算VN后验均值方差	$K N_{s} (6 \times 2^{Q} + 2 L d_{v} + 3)$
总复杂度	$I (K N_{s} (6 \times 2^{Q} + 8 L d_{v} + 3) + 4 M N L d_{f})$

表1

图6

图7

参考文献 15

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面向6G的新型多址与波形技术

New multiple access and waveform technology for 6G

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