基于DEKF联合估计的CD3S信号解调算法  

Demodulation of CD3S signals based on DEKF joint estimation

作　　者：袁国刚 王永川 陈鹏 高喜俊 YUAN Guogang;WANG Yongchuan;CHEN Peng;GAO Xijun(UAV Engineering Department,Shijiazhuang Campus,Army Engineering University of PLA,Shijiazhuang 050003,China)

机构地区：[1]中国人民解放军陆军工程大学石家庄校区无人机工程系,河北石家庄050003

出　　处：《系统工程与电子技术》2018年第9期2119-2123,共5页Systems Engineering and Electronics

基　　金：武器装备预先研究项目资助课题

摘　　要：针对实值混沌直接序列扩频(chaotic direct sequence spread spectrum,CD3S)信号同步难、解调难的问题,利用混沌码同步与信息码解调间的关联性,提出了一种基于双扩展卡尔曼滤波联合估计的CD3S信号解调算法。算法采用双扩展卡尔曼滤波结构,交替进行混沌码估计与信息码估计,通过联合估计完成混沌扩频码同步,并实现信息码的解调。考虑到信息码状态相互独立造成的卡尔曼增益退化问题,算法改进了信息码估计时的卡尔曼增益计算方法。仿真结果表明,该算法可以实现CD3S信号的正确解调,改进卡尔曼增益解调可以有效改善CD3S系统的误码性能。As to the problem of difficulty in synchronization and demodulation of chaotic direct sequence spread spectrum（CD3 S）signals,a demodulation algorithm for CD3 Ssignals is proposed based on the dual extended Kalman filter joint estimation structure,taking advantage of the correlation between chaotic code synchronization and data symbol demodulation.The algorithm alternately conducts chaotic code estimation and data symbol estimation using dual extended Kalman filter structure,and accomplishes the synchronization and demodulation by joint estimation.Considering the degeneracy of Kalman gain caused by the mutual independence of data symbol state,the algorithm improves the calculation method of Kalman gain in the estimation of data symbol.Simulation results demonstrate that the algorithm can demodulate the CD3 Ssignals correctly and the new Kalman gain calculation method helps to achieve better bit error rate performance.

关 键 词：混沌直接序列扩频 解调算法 联合估计 扩展卡尔曼滤波 

分 类 号：TN911[电子电信—通信与信息系统]