面向6G快时变信道下OTFS系统的信号检测  

Signal Detection for OTFS Systems Under 6G Fast Time-Varying Channels

作　　者：邵加亮 李汀[1] 解培中[1] SHAO Jialiang;LI Ting;XIE Peizhong(College of Communication and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《移动通信》2024年第10期155-162,共8页Mobile Communications

基　　金：国家自然科学基金“基于量子机器学习的6G空频时非平稳信道估计和预编码技术研究”(62271265);国家自然科学基金“基于扩域的二维正交图分多址最佳跳频图设计方法研究”(62271266)。

摘　　要：OTFS调制可以有效解决无线信道的快速时变特性给信号检测带来的巨大挑战,可以为高速移动设备提供可靠的无线通信。针对最大似然算法直接应用于OTFS系统进行信号检测时复杂度过高的问题,提出基于并行干扰消除的最大似然检测算法。在延时多普勒域,信道呈现正交、稀疏、可分离特性,发送信号和信道信息呈现出二维卷积的形式。基于此性质同时利用已检测信号,在检测阶段去除已检测信号形成的干扰,降低最大似然算法的复杂度。在此基础上在发送端插入零值使得接收信号在延时方向实现多径分离,进一步降低算法的复杂度。数值仿真结果表明,所提算法在OTFS系统中能够实现高准确率的信号检测,可以有效对抗高速移动场景下的快时变信道。OTFS modulation effectively addresses the significant challenge posed by rapid time-varying characteristics of wireless channels,providing reliable wireless communication for high-speed mobile devices.To overcome the high computational complexity of applying the maximum likelihood algorithm directly to OTFS systems for signal detection,a parallel interference cancellation-based maximum likelihood detection algorithm is proposed.In the delay-Doppler domain,the channel exhibits orthogonal,sparse,and separable characteristics,presenting a two-dimensional convolution structure between transmitted signals and channel information.Leveraging this property and simultaneously using the detected signals,interference caused by the detected signals is removed during the detection phase,reducing the complexity of the maximum likelihood algorithm.Furthermore,zero values are inserted at the transmitter to achieve multipath separation in the delay direction,further reducing algorithm complexity.Numerical simulation results demonstrate that the proposed algorithm achieves high-accuracy signal detection in OTFS systems,effectively combating rapidly time-varying channels in high-speed mobile scenarios.

关 键 词：OTFS 快时变信道 并行干扰消除 最大似然检测 

分 类 号：TN929.5[电子电信—通信与信息系统]