四维直接序列扩频系统同步偏差敏感性分析  

Sensitivity Analysis of Synchronization Offset on Four-dimensional Direct Sequence Spread Spectrum System

作　　者：华博 刘玉杰 毛忠阳 康家方 刘锡国 HUA Bo;LIU Yu-jie;MAO Zhong-yang;KANG Jia-fang;LIU Xi-guo;无(School of War Service,Naval Aviation University,Yantai 264001,China;Navy Flight Recruitment Office,Beijing 100000,China;Graduate management team No.3,Naval Aviation University,Yantai 264001,China)

机构地区：[1]海军航空大学战勤学院航空通信教研室,山东烟台264001 [2]海军招飞办公室,北京100000 [3]海军航空大学研究生管理大队研究生三队,山东烟台264001

出　　处：《中国电子科学研究院学报》2020年第9期886-893,共8页Journal of China Academy of Electronics and Information Technology

基　　金：国家自然科学基金资助项目(61701518);山东省“泰山学者”建设工程专项经费基金资助项目(ts20081130)。

摘　　要：针对四维直接序列扩频系统对同步偏差敏感的问题,分析了同步偏差对系统输出信噪比(Signal-to-noise ratio,SNR)的影响,给出了系统判决时刻信噪比理论表达式。理论和仿真结果表明,相比于直接序列扩频系统,四维直接序列扩频系统对定时同步偏差更为敏感,在误码率为10^-5、同步偏差τ=0.2Tc时,传统直接序列扩频系统信噪比仅损失0.4dB,而四维直接序列扩频系统的信噪比损失达到3.7dB。当同步偏差大于Tc/2,四维直接序列扩频系统将无法正确解调。The theoretical expression of signal-to-noise ratio(SNR)for a four-dimensional Direct-sequence spread spectrum system was derived.The effect of timing synchronization offset on the output signal-to-noise ratio of the system at the decision time was analyzed.Theoretical and simulation result shows that,compared with direct sequence spread spectrum systems,the four-dimensional direct spread system is more sensitive to timing synchronization offset.When the bit error rate is 10^-5 and the synchronization offset isτ=0.2 Tc,the direct sequence spread spectrum system SNR loss is only 0.4 dB,while the signalto-noise ratio loss of the four-dimensional direct sequence spread spectrum system reaches 3.7 dB.When the synchronization timing offset is greater than Tc/2,the four-dimensional direct sequence spread spectrum system cannot demodulate correctly.

关 键 词：四维直接序列扩频系统 敏感性 同步偏差 信噪比损失 

分 类 号：TN911.6[电子电信—通信与信息系统]