散射通信系统中SNR自适应预测技术  

Signal-to-Noise Ratio Adaptive Prediction Technique in Troposcatter Communication Systems

作　　者：郭梦琪 孟颢 GUO Mengqi;MENG Hao(The 54th Research Institute of CETC,Shijiazhuang 050081,China;Science and Technology on Communication Networks Laboratory,Shijiazhuang 050081,China)

机构地区：[1]中国电子科技集团公司第五十四研究所,河北石家庄050081 [2]通信网信息传输与分发技术重点实验室,河北石家庄050081

出　　处：《无线电工程》2023年第6期1450-1457,共8页Radio Engineering

基　　金：国家部委基金资助项目。

摘　　要：对流层散射通信的快衰落特性导致接收信号信噪比(Signal-to-Noise Ratio,SNR)不断变化,根据时变SNR进行自适应编码调制,可以使业务速率实时跟随SNR的变化而改变,在保证可靠传输的前提下有效提升通信吞吐量。针对散射通信系统自适应编码调制的需求,在归一化最小均方(Normalization Least Mean Square,NLMS)算法和递归最小二乘(Recursive Least Square,RLS)算法的基础上,提出了改进递归最小二乘(Modified Recursive Least Square,MRLS)SNR预测算法。SNR预测算法可以解决接收端估计的SNR反馈到发送端的延迟问题。经过仿真和外场实验测试,相比NLMS算法和RLS算法,所提出的MRLS算法具有更小的SNR预测误差。采用所提出的MRLS算法进行自适应编码调制流程后,相比NLMS算法和RLS算法,在外场实验中分别可获得约0.4、2 Mb/s的平均业务速率提升,证明了所提出算法的性能优势。In troposcatter communication systems,the fast fading characteristics lead to the change of Signal-to-Noise Ratio(SNR)for receiving signals.Using adaptive coding and modulation according to the time-varying SNR can make the link rate change in real time with the change of SNR,so that the transmission throughput can be efficiently improved with the guarantee of reliability.To meet the requirement of adaptive coding and modulation in troposcatter communication systems,a Modified Recursive Least Square(MRLS)SNR prediction algorithm is proposed based on Normalization Least Mean Square(NLMS)algorithm and Recursive Least Square(RLS)algorithm.The SNR prediction algorithm can solve the problem of time delay because the estimated SNR should be fed back from receiver to transmitter.Through simulation and outfield experimental test,the proposed MRLS algorithm has smaller SNR prediction error compared with NLMS algorithm and RLS algorithm.After applying the proposed MRLS algorithm in the process of adaptive coding and modulation,the proposed algorithm has approximately 0.4 Mb/s and 2 Mb/s average link rate improvement compared with NLMS and RLS,which verifies the performance advantage of the proposed algorithm.

关 键 词：散射通信 自适应编码调制 信噪比预测 

分 类 号：TN911[电子电信—通信与信息系统]