一种采用相位补偿的线谱相干检测器

A coherent tonal detector using phase compensation

分析了加窗和实信号情况下相干线谱检测器的检测性能。从频谱泄漏现象出发,通过对实信号做加窗处理,有效地降低了信号傅里叶变换后频谱泄漏的旁瓣级,提升了弱信号的探测能力;针对分段处理时同一频率不同数据段出现的相位差,采用相位补偿的方法,实现了各段数据的相干叠加。理论分析和计算机仿真表明,相比于平均功率谱检测器(Average Power Processor,AVGPR),加窗相位补偿检测器(Window Phase-Compensated Processor,WPCPR)有10 lg L(L为分段数)信噪比的提高,从而拓宽了相干线谱检测的适用范围。此外,还从频域波束形成的角度,给出了WPCPR能提高信噪比的一种物理解释,并指出了仿真中信噪比增益与理论值存在差异的原因。

This paper analyzes the detection performance of the coherent line-spectrum detector when the input data is real and windowed. Starting with spectral leakage, the method proposed in this paper effectively reduces the sidelobe level of leakage and hence improves the detection performance of weak real signals through windowing. Phase difference between segments of data at the same frequency is correspondingly compensated, which results in the coherent integration of data. Considering the situation of windowing and real-data, theoretical analysis and simulation show that the Window Phase-Compensated Processor （WPCPR） of this paper can gain 10 lg L （L is the number of segments） more signal-to-noise ratio （SNR） when compared with the Average Power Processor （AVGPR）, thus widening the scope of coherent line-spectrum detection. Furthermore, this paper gives a physical interpretation of the new method from the perspective of frequency domain beamforming and points out the reason why the SNR improvement is not good as predicted.