外辐射源雷达利用非合作照射源信号探测目标,参考信号提纯和监测信号杂波抑制是实现目标信号检测的关键.该文针对数字电视外辐射源雷达接收系统中存在的采样速率偏差问题,首先建立信号模型,从理论上分析了采样速率偏差对参考信号重构性能的影响,然后探讨了采样速率偏差对时域杂波抑制和相关匹配接收的影响.仿真结果说明存在采样速率偏差时,提高接收端采样速率可以降低参考信号的重构误码率;不同的时域杂波抑制算法对采样速率偏差的表现不同;采样速率偏差对时域杂波抑制的影响较大,对相关匹配接收的影响较小.实测数据处理验证了上述结论的正确性,为提高数字电视外辐射源雷达的目标探测性能提供了理论依据.%Passive radar makes full use of non-cooperative illumination source to detect targets. Reference signal purification and clutter suppression of the surveillance signal are two key steps to achieve target signal detection. To solve the problem of the sampling frequency offset in digital TV based passive radar, the signal model is first established, and the impact of the sampling frequency offset on the performance of the reference signal reconstruction is analyzed. Then how the sampling frequency offset affects the clutter suppression and the target correlation matching is mainly investigated. The simulation results show that improving the sampling frequency can reduce the symbol error rate of the reconstructed signal. Different temporal clutter suppression algorithms perform differently under the existence of sampling frequency offset. The sampling frequency offset has a greater impact on the temporal clutter rejection performance and less effect on correlation matching. Finally, the analysis results are verified by the measurement data, which also provide theoretical basis on improving the target detection performance of digital TV based passive radar.
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