基于改进广义正交匹配追踪的低地球轨道卫星MIMO-OTFS系统的信道估计方法  

Channel estimation method for low earth orbit satellite MIMO-OTFS system based on improved generalized orthogonal matching pursuit

作　　者：雷芳[1,2] 牛永才 LEI Fang;NIU Yongcai(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Mobile Communication Protocol Innovation Laboratory,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065 [2]重庆邮电大学移动通信协议创新实验室,重庆400065

出　　处：《计算机应用》2024年第8期2514-2520,共7页journal of Computer Applications

基　　金：重庆市自然科学基金资助项目(cstc2021jcyj-msxmX0454)。

摘　　要：针对基于多输入多输出(MIMO)技术和正交时频空间(OTFS)调制的低地球轨道卫星系统的复杂性带来的信道估计困难问题,提出一种基于改进广义正交匹配追踪(GOMP)的信道估计方法。根据单输入单输出(SISO)-OTFS系统的输入输出关系和低地球轨道卫星信道的传播特性,建立一种基于MIMO-OTFS的低地球轨道卫星信道模型,并将系统的信道估计问题转化为稀疏信号的恢复问题。考虑到传统的GOMP算法存在对稀疏度的过度依赖和对稀疏信号的重构精度差等问题,所提方法结合了分段弱正交匹配追踪(SWOMP)的弱选择思想和广义Jaccard系数的相似性准则,以快速准确地重建稀疏信号。仿真结果表明,当天线数为16且导频开销比为0.5时,与正交匹配追踪(OMP)算法相比,所提方法的归一化均方误差(NMSE)降低了约2.5 dB,误码率(BER)降低了约5 dB。Aiming at the difficulty of channel estimation caused by the complexity of Low Earth Orbit(LEO)satellite systems based on Multiple-Input Multiple-Output(MIMO)technology and Orthogonal Time-Frequency Space(OTFS)modulation,a channel estimation method based on improved Generalized Orthogonal Matching Pursuit(GOMP)was proposed.According to the input-output relationship of the Single-Input Single-Output(SISO)-OTFS system and the propagation characteristics of the LEO satellite channel,a low-orbit satellite channel model based on MIMO-OTFS was established,and the channel estimation problem of the system was transformed into a sparse signal recovery problem.Considering that the traditional GOMP algorithm has the problems of excessive dependence on sparsity and poor reconstruction accuracy of sparse signals,the proposed method combined the weak selection idea of Stagewise Weak Orthogonal Matching Pursuit(SWOMP)and the generalized Jaccard coefficient-based similarity criterion for fast and accurate reconstruction of sparse signals.The simulation results show that when the number of antennas is 16 and the pilot overhead ratio is 0.5,compared with the Orthogonal Matching Pursuit(OMP)algorithm,the proposed method reduces the Normalized Mean Square Error(NMSE)by about 2.5 dB,and reduces the Bit Error Rate(BER)by approximately 5 dB.

关 键 词：正交时频空间 低地球轨道卫星 多输入多输出 信道估计 广义正交匹配追踪 

分 类 号：TN927[电子电信—通信与信息系统]