基于频谱幅度起伏特性的微弱信号检测方法研究

该文将非线性后置处理思想引入至最小方差无失真响应(MVDR)的空间能量谱计算中，并给出其实现方法，即最终空间能量谱通过将各窄带阵列输出结果取倒数并求和得到，它不需要阵列噪声和目标信号的任何先验信息，只要阵列噪声的频谱在频段间的幅度起伏大于目标信号的频谱幅度起伏，该方法就能取得较常规处理方法更好的信号检测性能。根据最优信号检测理论，初步验证了非线性后置处理方法的性能，并利用仿真和实际数据进一步检验了其有效性，分析结果表明:非线性后置处理方法的处理增益较常规方法提高约3.5dB-4dB。

Research of the Method for the Weak Signal Detection Based on the Amplitude Fluctuation Property of the Frequency Spectrum

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.