准正交多值PN码M元扩频通信系统及其性能分析  

The design and performance analysis of the M-ary spread spectrum system based on the quasi-orthogonal multi-PN code

作　　者：熊海良[1] 肖竹[1] 蔡成林[2] 田红心[1] 易克初[1] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071 [2]中国科学院研究生院,北京100049

出　　处：《西安电子科技大学学报》2010年第1期80-85,共6页Journal of Xidian University

基　　金：国家自然科学基金资助项目(60572148;60702060);湖南省自然科学基金资助项目(07JJ6105);高等学校学科创新引智计划资助项目(B08038)

摘　　要：提出了一种扩频方案.通过格雷互补序列树型扩展算法构造对偶多值PN码混合矩阵,并利用该混合矩阵对信息序列进行M元扩频,这种扩频方式能有效地提高频带效率和抗截获性能,比直接序列扩频具有3 dB的性能改善.针对伪码较长的扩频通信系统码同步计算复杂度高、硬件实现困难的缺点,提出了一种基于两级FFT的快速捕获算法,其计算复杂度与传统的PMF-FFT算法相比能下降一个数量级.通过同相、正交支路进行交叉混合数据解扩,能有效消除载波相位偏移对系统性能的影响.We propose a novel class of M-ary spread spectrum based on the quasi-Orthogonal multi-PN code. A hybrid matrix based on the Golay complementary sequence is deduced and used for the M-ary spread spectrum, which greatly enhances the band efficiency and robustness, and compared with the spread spectrum technique, it provides a larger spread gain and a stonger anti-intercept capture capability. In order to overcome the difficulties incurred by a long PN code spread spectrum system such as high computational complexity of synchronization and complicated hardware realization, a novel fast acquisition algorithm based on the 2-stage FFT is presented whose complexity is largely reduced compared with the conventional PMF-FFT algorithm. The receiver can effectively eliminate distortion caused by phase offset of the carrier using quadrature subchannel information for intersect data dispreading.

关 键 词：M元扩频 准正交多值PN码 伪码捕获 频偏纠正 

分 类 号：TN914.53[电子电信—通信与信息系统]