WiFi 外辐射源雷达信号模糊函数及副峰抑制分析

WiFi (Wireless Fidelity)信号具有覆盖范围广、带宽大等优点，利用其作为外辐射源进行探测可达到较高的距离与多普勒分辨率。该文分析了典型WiFi 信号的结构，建立了描述信号的数学模型，并针对双基地外辐射源雷达应用，探讨了典型WiFi 信号结构与其模糊函数特性的关系。同时根据模糊函数副峰出现的时频及幅度特征，结合信号构成分析了其产生机理，并提出了一种基于直达波提纯的副峰抑制方法，从而可避免副峰干扰在目标探测中带来的虚警。仿真结果表明了该信号分析与处理方法的有效性。 

Ambiguity Function Analysis and Side Peaks Suppression of WiFi Signal for Passive Radar

WiFi (Wireless Fidelity) is widely deployed all the world. When it is utilized as external illuminaor in Passive Radar, its broadband singal make the high resolution of detection be obtained in both the range and Doppler domains. In this paper, the typical WiFi signal format and its characters are analyzed, then the theoretical signal model is setup. Based on the theory of bistatic passive radar, the relationship between typical IEEE 802.11 signals format and the characters of its Ambiguity Function (AF) is analyzed. Moreover, the position and amplitude of side peaks in time and frequency domain is analyzed and its causes from the signal structure is also discussed. In this paper, a method for suppressing the side peaks based on the correction of direct-path reference signal is proposed, therefore to avoid the false alarm brought in target detection caused by side peak interference. Experimental results valid the proposed signal processing method.