色噪声中低信噪比单音正弦信号的频率估计

Frequency estimation of single sinusoid in colored noise at low SNR

针对色噪声条件下的低信噪比单音信号频率估计问题,提出了一种色噪声功率谱补偿算法。该算法利用色噪声功率谱期望值的慢变特点,通过非线性滤波比较功率谱抽头与其邻域抽头均值的大小,消除色噪声功率谱起伏对频率估计的影响,进而采用极大值搜索给出频率估计。对所用非线性处理的稳定性进行了理论分析,并通过计算机仿真给出了算法估计精度,从而验证了算法的有效性。

A power spectrum compensating algorithm is presented for frequency estimation of single sinusoids in colored noise at low SNR. Due to its slowly changing expectation, the fluctuation of power spectrum is suppressed by comparing every frequency bin and a set of nearby bins, a process referred as nonlinear-filtering here. The coarse frequency estimation will then be given through peak-searching algorithm based on nonlinearfiltered power spectrum. The new algorithm is proved stable, although nonlinear process has been applied, by theoretical analysis. The result of computer simulation indicates that the new algorithm can work very well at lower signal-to-noise ratio.