An algorithm based on eigenanalysis technique and Walsh-Hadamard transform （WriT） is proposed. The algorithm contains two steps. Firstly, the received sequence is divided into temporal windows, and a covariance matr...An algorithm based on eigenanalysis technique and Walsh-Hadamard transform （WriT） is proposed. The algorithm contains two steps. Firstly, the received sequence is divided into temporal windows, and a covariance matrix is computed. The linear feedback shift register （LFSR） sequence is reconstructed from the first eigenvector of this matrix. Secondly, equations according to the recovered LFSR sequence are constructed, and the Walsh spectrum corresponding to the equations is computed. The feedback polynomial of LFSR is estimated from the Walsh spectrum. The validity of the algorithm is verified by the simulation result. Finally, case studies are presented to illustrate the performance of the blind reconstruction method.展开更多
非合作通信条件下,针对扰码器初始参数估计问题,第三方需在通信参数不完全所知的情况下,对抗干扰、重建反馈多项式和估计初始状态,以重建扰码器。首先,根据对偶码特性和多信息流抗干扰技术,构造具有低误码率特性并包含扰码器特征参数的...非合作通信条件下,针对扰码器初始参数估计问题,第三方需在通信参数不完全所知的情况下,对抗干扰、重建反馈多项式和估计初始状态,以重建扰码器。首先,根据对偶码特性和多信息流抗干扰技术,构造具有低误码率特性并包含扰码器特征参数的新序列;其次,采用低重量倍式搜索算法和基于对偶码的快速相关攻击算法,分别对新构造序列的反馈多项式和初始状态进行估计;最后,根据新序列与扰码的关系,重建扰码器初始参数。仿真结果表明,算法可在信噪比为0 d B条件下有效对抗噪声干扰并重建扰码器。展开更多
基金supported by the National Natural Science Foundation of China(61072120)
文摘An algorithm based on eigenanalysis technique and Walsh-Hadamard transform （WriT） is proposed. The algorithm contains two steps. Firstly, the received sequence is divided into temporal windows, and a covariance matrix is computed. The linear feedback shift register （LFSR） sequence is reconstructed from the first eigenvector of this matrix. Secondly, equations according to the recovered LFSR sequence are constructed, and the Walsh spectrum corresponding to the equations is computed. The feedback polynomial of LFSR is estimated from the Walsh spectrum. The validity of the algorithm is verified by the simulation result. Finally, case studies are presented to illustrate the performance of the blind reconstruction method.
文摘非合作通信条件下,针对扰码器初始参数估计问题,第三方需在通信参数不完全所知的情况下,对抗干扰、重建反馈多项式和估计初始状态,以重建扰码器。首先,根据对偶码特性和多信息流抗干扰技术,构造具有低误码率特性并包含扰码器特征参数的新序列;其次,采用低重量倍式搜索算法和基于对偶码的快速相关攻击算法,分别对新构造序列的反馈多项式和初始状态进行估计;最后,根据新序列与扰码的关系,重建扰码器初始参数。仿真结果表明,算法可在信噪比为0 d B条件下有效对抗噪声干扰并重建扰码器。
