基于类间功率谱差的FRFT-TDCS门限判决算法  

Threshold decision algorithm for FRFT-TDCS based on power spectral difference between classes

作　　者：任清华[1,2] 徐兵政 王桂胜 胡诗骏[3] 刘洋 REN Qinghua;XU Bingzheng;WANG Guisheng;HU Shijun;LIU Yang(Information and Navigation College,Air Force Engineering University,Xi’an 710077,P.R.China;CETC Key Laboratory of Aerospace Information Applications,Shijiazhuang 050081,P.R.China;95129 Troops of PLA,Kaifeng 475000,P.R.China)

机构地区：[1]空军工程大学信息与导航学院 [2]中国电子科技集团航天信息应用技术重点实验室 [3]95129部队

出　　处：《重庆邮电大学学报（自然科学版）》2018年第5期642-648,共7页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家自然科学基金(61401499);新技术研究高校合作项目(KX162600022)~~

摘　　要：针对分数阶傅里叶变换域通信系统采用传统门限判决算法难以有效剔除多分量线性调频干扰的问题,根据高斯白噪声和多分量线性调频干扰分数阶傅里叶变换域功率谱特征,提出了基于类间功率谱差的门限判决算法。该算法利用了分数阶傅里叶变换不影响高斯白噪声的统计特性,在分数阶傅里叶变换域的三维频谱上自适应地确定门限值,既可以有效对多分量线性调频干扰频谱剔除,又解决了分数阶傅里叶变换的变换阶次对门限判决带来的不利影响。仿真结果表明,该算法在双极性调制和循环移位键控调制下,对多分量线性调频干扰剔除的有效性,尤其在大干信比情况下,误码率的提升尤为明显,对提高分数阶傅里叶变换域通信系统抗多分量线性调频干扰的能力具有一定的实用价值。In order to overcome the problem that transform domain communication system based on fractional Fourier transform(FRFT-TDCS)with traditional threshold decision method is difficult to eliminate multi-component linear frequency modulation(LFM)interference.According to the power spectrum of Gauss white noise and interference,a threshold decision algorithm based on the power spectrum difference between classes is proposed.The algorithm takes advantage of the fractional Fourier transform that does not affect the statistical properties of Gauss white noise.It can effectively determine the threshold value in the three-dimensional spectrum of the FRFT domain,which can effectively eliminate the interference spectrum and solve the negative influence of the FRFT transformation order on the threshold decision.The simulation results show that the algorithm is effective for jamming in bipolar modulation and cyclic shift keying modulation.Especially in the case of large interference energy-to-signal energy ratios,the improvement of bit error rate is particularly evident.It has practical value for improving the ability of FRFT-TDCS to resist LFM interference.

关 键 词：分数阶傅里叶变换 变换域通信系统 线性调频干扰 门限判决 类间功率谱差 

分 类 号：TN973[电子电信—信号与信息处理]