基于CDR数字音频广播的外辐射源雷达信号模糊函数分析与处理

Ambiguity Function Analysis and Processing for Passive Radar Based on CDR Digital Audio Broadcasting

CDR(China Digital Radio)数字音频广播是我国自主研发的FM频段(87-108 MHz)数字音频广播新标准,它兼容我国现有模拟FM广播的频谱规划,能够满足我国FM频段声音广播从模拟到数字平滑过渡的需求。该文从CDR信号结构入手,重点探讨了基于该广播的外辐射源雷达信号特性及相关处理方法。首先分析其信号特性以及作为外辐射源雷达照射源的模糊函数特性;然后针对因循环前缀引起的模糊函数副峰、同步信号引起的多普勒模糊带以及信号频谱不连续导致的距离副峰对目标探测的不利影响,分别提出了相应的副峰抑制方法,并通过仿真验证了该方法的有效性。

China Digital Radio （CDR） broadcasting is a new standard of digital audio broadcasting of FM frequency （87–108 MHz） based on our research and development efforts. It is compatible with the frequency spectrum in analog FM radio and satisfies the requirements for smooth transition from analog to digital signal in FM broadcasting in China. This paper focuses on the signal characteristics and processing methods of radio-based passive radar. The signal characteristics and ambiguity function of a passive radar illumination source are analyzed. The adverse effects on the target detection of the side peaks owing to cyclic prefix, the Doppler ambiguity strips because of signal synchronization, and the range of side peaks resulting from the signal discontinuous spectrum are then studied. Finally, methods for suppressing these side peaks are proposed and their effectiveness is verified by simulations.