Research of the Method for the Weak Signal Detection Based on the Amplitude Fluctuation Property of the Frequency Spectrum
基于频谱幅度起伏特性的微弱信号检测方法研究

Application of the non-linear post-processing method in improving the weak signal detection performance of the broadband Minimum Variance Distortionless Response (MVDR) is researched fully. The final spatial energy spectrum can be obtained by summing the reciprocal of the output power of every narrowband frequency bin. There is no need for the method proposed in this paper to know any prior information about the array noise and the target signal. The processing gain by this method compared to the general broadband MVDR can be obtained as long as the amplitude fluctuation of the array noise frequency spectrum is severer than that of the target signal. Based on the optimal signal detection theory, a method for analyzing the performance of the non-linear post-processing is also brought forward. Simulation and real data are used to validate the effectiveness of the non-linear post-processing method. Analysis results show that 3.5dB-6dB processing gain compared to the general broadband MVDR can be reached with the proposed method.