一种扩展水下扩频信号多普勒容限方法  

A Method for Extending Doppler Tolerance of Underwater Spread Spectrum Signal

作　　者：苏建军[1,2] 冯西安[1] 白晓娟[1] 李志伟[1,2] 

机构地区：[1]西北工业大学航海学院 [2]中国人民解放军91388部队

出　　处：《鱼雷技术》2012年第6期424-427,共4页Torpedo Technology

基　　金：教育部博士点基金(20106102110011)

摘　　要：扩频信号的模糊函数图呈图钉型,对多普勒频移比较敏感,影响了扩频信号的使用性能。本文分析了扩频信号的多普勒敏感性问题,提出了一种基于回波预处理的方法。首先将回波信号经过正交混频得到零中频I,Q通道信号,然后将零中频I,Q通道信号送入多普勒预处理系统进行处理,通过时间延迟处理方法得到的2个输出信号,分别经过匹配滤波器后再进行合并处理,脉压输出相关函数中不含多普勒频移和时间乘积,消除了多普勒频移对匹配滤波器输出的影响。数值仿真证明了该方法的有效性,且具有实现简单,运算量小的优点。Spread spectrum signal is sensitive to Doppler frequency shift, which limits the service property of the spread spectrum signal. This paper proposes a method for echo pre-processing by analyzing the sensitivity of spread spectrum signal to Doppler frequency shift. Zero intermediate frequencyI, Q channel signals are obtained through the orthogonal frequency mixing of echo. Then the signals are processed in the echo pre-processing system to obtain two output signals by time-delay processing method. The two output signals are further processed by a matching filter to achieve a combined signal which doesn＇t contain Doppler frequency shift and time product. Numerical simulation demonstrates the validity of the proposed method with simplicity and smaller amount of computation.

关 键 词：多普勒容限 扩频信号 模糊度函数 匹配滤波器 预处理系统 

分 类 号：TJ630.34[兵器科学与技术—武器系统与运用工程]