一种短波混沌跳频的捕获方法  

An acquisition method for short-wave chaotic FH

作　　者：甘良才[1] 周敏锋[1] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430072

出　　处：《电波科学学报》2002年第4期404-411,共8页Chinese Journal of Radio Science

基　　金：国家自然科学基金资助项目 (6 9772 0 15 )

摘　　要：提出了采用离散傅立叶变换 (DFT)技术的短波混沌FH/DQPSK系统的快速扫描捕获法 ,并分别在多音干扰、多个邻台情况下进行了数值模拟与分析 ,同时与位移等待式自同步法的捕获性能进行了比较 ;分析了DFT变换器舍入误差对捕获性能的影响。研究结果表明 :当跳频频点数为 16、跳频速率为 2 5 6 0跳 /秒、多音干扰数目为 15或 16个邻台同时工作时 ,一个切普时间内扫描 4个频点的快速扫描捕获法的平均捕获时间分别为 5 .7ms和 11.2ms ,与位移等待式自同步法相比 ,其平均捕获时间分别缩短了 5 0 .4 %和 6 7.4 %。当舍入误差的方差与信道中加性白高斯噪声(AWGN)的方差比 ρ =6时 ,捕获时间为 6 4.3ms,为 ρ =0时的 11.9倍。By adopting Discrete Fourier Transforms (DFT) technology, a fast scanning acquisition method for short wave chaotic FH/DQPSK communication system is presented in this paper. Numerical analysis and simulation are carried out under the condition of multitone interference and several neighboring stations,and compared with that of displacement waiting and searching self synchronization method. The affection of the round off errors of DFT transformer to the performance of acquisition is analyzed. The results showsd that, when the number of FH frequency point is 16, FH speed rate is 2560hop/s, as the number of active multitone interfering neighboring stations is 15 or 16 , the average acquisition time with this method scanning 4 frequency points in one chip is 5.7ms and 11.2ms, resulting 50.4% and 67.4% reduction compared with the displacement waiting and searching self synchronization method, respectively. When SNR is 0dB and the ratio ρ of the variance of round off errors to the variance of AWGN in channel is 6, the acquisition time is 64.3ms which is 11.9 times the acquisition time when ρ is 0.

关 键 词：短波 混沌跳频 捕获方法 跳频通信 

分 类 号：TN914.4[电子电信—通信与信息系统]