中文摘要：

针对正弦波频率估计对准确性的要求,对Kay算法进行改进,研究了一种全相位Kay算法.首先,讨论Kay算法在低信噪比下的缺陷,其次利用全相位频谱分析中可以降低旁瓣泄漏以及相位不变性的优点,并结合Kay算法及相位展开,得到全相位Kay算法,可以在较低信噪比（SNR〈7 dB）条件下较好地估计正弦波频率,在中高信噪比条件下（SNR〉7 dB）,估计精度达到克拉美-罗限,并且在所有的频率区域性能稳定.最后,通过MATLAB仿真验证,该算法的均方根误差比Kay算法改进了4 dB,表现出了更佳的性能.

英文摘要：

According to the sinusoid frequency estimation for accuracy requirements,a new method of all phase Kay algorithm of Sinusoid frequency estimation is put forward in order to improve the Kay algorithm.Firstly,the drawback of Kay algorithm is introduced,then an all phase Kay（ApKay） algorithm is proposed,using the excellent performance in suppressing spectral leakage and the advantage of phase invariant of all phase FFT（ApFFT）,combing Kay algorithm and phase unwrapping.The new ApKay algorithm is applied to the frequency estimation of sinusoid,a better estimation can be obtained at low signal-to-noise ratios（SNR）,the estimated accuracy attains the Cramer-Rao lower bound（CRLB） at middle and high SNR,and the performance is stable in the whole frequency region.The simulation results show that the mean square error of the ApKay algorithm is 4dB better than that of Kay algorithm,implying that the method achieves a better performance.