针对噪声条件下的单通道多分量正弦调频(SFM)信号,该文提出一种信号分离和参数提取方法。利用正弦调频信号的广义周期性进行奇异值分解,以求出分量信号的调制频率;通过离散点搜索,估计出分量信号的调频(FM)初始相位、调制指数及载频,并对这些估计值利用信赖域算法进行优化,减小误差;利用内积计算,估计分量信号的幅度和初始相位。此外,还利用自相关矩阵特征值分解估计混合信号的信噪比(SNR),并根据信噪比确定停止分解的阈值。在仿真与分析中,针对具体的信号详细说明了该方法的各步骤,并在不同信噪比条件下分析了该方法的参数估计精确度。
A method of single channel source separation and parameters estimation of multi-component Sinusoid Frequency Modulation (SFM) signal is proposed, the generalized periodic is derived and it can be used to estimate the modulation frequency by singular value decomposition. The estimated modulation frequency can be used as a known quantity, then by searching the discrete points and optimization calculating with the trust region algorithm, the Frequency Modulation (FM) initial phase, the FM index and the carrier frequency are determined. Finally, the amplitude and the initial phase can be determined by calculating the inner product. In addition, the proposed method can estimate the Signal Noise Ratio (SNR) by using eigenvalue decomposition, and the SNR can be used to determine the threshold adaptively. In the simulation, the method is demonstrated by separating a specific signal, and it is supposed that the proposed method is effective in different SNRs.