多径信道下基于CMA算法的SOQPSK-TG盲均衡  

Blind Equalization Based on Constant Modulus Algorithm for SOQPSK-TG in Multipath Channel

作　　者：廖红姣 赖鹏辉 董蕤 王世练[1] 张炜[1] 马艳敏 LIAO Hongjiao;LAI Penghui;DONG Rui;WANG Shilian;ZHANG Wei;MA Yanmin(College of Electronic Science and Technology,National University of Defense Technology,Changsha 410073,China;College of Electronic Information Engineering,Beijing Jiaotong University,Beijing 100044,China;Unit 31006,PLA,Beijing 100089,China)

机构地区：[1]国防科技大学电子科学学院,湖南长沙410073 [2]北京交通大学电子信息工程学院,北京100044 [3]中国人民解放军31006部队,北京100089

出　　处：《无线电工程》2022年第4期550-554,共5页Radio Engineering

基　　金：国家自然科学基金(61702536)。

摘　　要：针对遥测链路“低仰角”场景,研究多径信道下使用恒模算法(Constant Modulus Algorithm,CMA)进行盲均衡给部分响应成形偏移正交相移键控(SOQPSK-TG)检测带来的性能增益。数字下变频后通过CMA直接确定均衡器抽头系数,不需要载波、定时同步的先验信息,利于实现。仿真分析时,对均衡完成后的信号进行载波、定时同步和检测,分析过程和结果对接收机设计有指导意义。仿真结果表明,在3种典型“低仰角”航空遥测——滑行、起飞和远航场景中,使用CMA盲均衡均能有效缓解多径衰落对同步、检测的影响,与未均衡时相比,在滑行场景有3~3.1 dB的性能增益,在起飞场景有0.9~1 dB的性能增益,在远航场景有10.8~11 dB的性能增益。To improve the performance gain of receiver of Shaped Offset QPSK,version TG(SOQPSK-TG)in low-elevation-angle scenario,Constant Modulus Algorithm(CMA)for blind equalization under multipath channels is used.After digital down-conversion,the equalizer tap coefficients are directly determined through CMA without the prior information of carrier and timing synchronization,which is conducive to implementation.During simulation analysis,the carrier,timing synchronization and detection of the signal after equalization are completed,the analysis process and results have guiding significance for the design of receiver.Simulation results show that using CMA for blind equalization in three typical low-elevation-angle aeronautical telemetry scenarios,i.e.taxiing,take-off and far-flight,can effectively alleviate the impact of multipath fading on synchronization and detection.As compared with equalizer-off,the performance gain is 3~3.1 dB in taxiing scenario,0.9~1 dB in take-off scenario,and 10.8~11 dB in far-flight scenario.

关 键 词：恒模算法 SOQPSK-TG 航空遥测 多径信道 自适应均衡 

分 类 号：TN92[电子电信—通信与信息系统]