OFDM系统中基于压缩感知恢复由限幅和HPA产生的非线性失真研究  

Research on Recovery of Clipping and HPA Nonlinear Distortion Based on Compressive Sensing in OFDM Systems

作　　者：杨霖[1,2] 宋坤 YANG Lin;SONG Kun(Key Laboratory of National Communication Technology,University of Electronic Science and Technology,Chengdu,Sichuan 611731,China;Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory,The 54th Research Institute of China Electronics Technology Group Corporation,Shijiazhuang,Hebei 050081,China)

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,四川成都611731 [2]中国电子科技集团公司第五十四所通信网信息信传输与分发技术重点实验室,河北石家庄050081

出　　处：《电子学报》2018年第5期1078-1083,共6页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61370012;No.61571082);国家科技重大专项课题(No.2016ZX03001015-004)

摘　　要：正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的主要缺点之一就是有较高的峰均功率比(Peak to Average Power Ratio,PAPR),降低了功率放大器(High Power Amplifier,HPA)的工作效率,同时HPA引入的非线性失真,恶化了系统的误比特率(Bite Error Rate,BER)性能.本文所提算法将限幅和HPA引入的非线性失真视为一个整体来考虑,利用与限幅噪声在时域上的近似稀疏性,对整个非线性过程进行建模.发送端通过限幅降低了OFDM信号的PAPR,在接收端,选取受噪声干扰小的可靠性观测向量,最小化信道噪声的影响,基于非线性模型计算得到的参数,利用压缩感知(Compressive Sensing,CS)算法能有效地恢复总的非线性失真信号,提升了系统的BER性能.One of the main drawbacks in orthogonal frequency division multiplexing （OFDM） systems is high peak to average power ratio （PAPR） which reduces the efficiency of high power amplifier （HPA）,and the nonlinear distortion caused by HPA will degrade the bite error rate （BER） of the system.The proposed scheme of this paper considers the nonlinear distortion caused by clipping and HPA as a whole,and models the whole nonlinear process utilizing the sparsity in time domain similar to the clipping noise.The PAPR of OFDM signal is reduced by clipping at the transmitter,and for the receiver,reliable observations contaminated by less channel noise are selected to minimize the influence of channel noise,and compressive sensing （CS） algorithm is applied to effectively recover the total nonlinear distortion signal with the parameters calculated from the nonlinear model,which can improve the BER performance of the system.

关 键 词：正交频分复用 峰均功率比 限幅 非线性失真恢复 压缩感知 

分 类 号：TN919.3[电子电信—通信与信息系统]