基于复倒谱技术的无源雷达直达波提纯方法

A Direct-path-wave Purified Approach to Passive Radar Based on Cepstrum Technique

利用民用FM广播信号为无源雷达的外辐射源时,由于信号在空间传输时产生严重的多径干扰,导致接收站获取的直达波参考信号与目标反射的回波在后继匹配滤波时出现失配现象,严重影响了雷达的目标检测性能。文中首先建立了基于FM广播外辐射源的双基地雷达模型;然后提出了一种在复倒谱域对直达波参考信号进行提纯处理后再进行匹配滤波的方法;最后给出了一个基于FM广播的外辐射源雷达实验系统,通过该实验系统采集的数据进行仿真,其结果表明了该方法与未提纯时相比,输出信噪比约有6 dB的改善,在工程上有参考价值。

When FM broadcast transmitter is regarded as extra irradiation source, multipath interference will lead to mismatch between the direct-path-wave reference signal and the echo reflected from target during matching filter, and then it will degrade the performance of moving target detection. First of all, a bistatic radar model based on FM broadcast illuminator is built in this paper. Secondly, the method which the direct-path-wave reference signal is purified by cepstrum technique is in detail introduced to solve this problem. Finally, an experimental system based on regarding FM broadcast transmitter as extra irradiation source is schemed, Simulation results show the proposed approach has about 6 dB improvement in output signal to noise ratio, There is worthy of considering in engineering.