非整周期采样信号频率估计的相频匹配方法

Phase and frequency matching method for the frequency estimation of sampling signals with non-integer period

为提高非整周期采样信号的频率估计精度,提出一种非整周期采样信号频率估计的相频匹配方法。首先,为抑制信号非整周期采样对自相关的影响,对采样信号进行加窗自相关;其次,根据加窗自相关信号初相位为零的特点生成参考信号,实现参考信号与加窗自相关信号的相位匹配;最后,根据柯西不等式,利用参考信号和加窗自相关信号构造反映参考信号和加窗自相关信号频率匹配程度的误差函数,误差函数最小值对应的频率即为信号频率估计值。计算验证和LFMCW雷达测距实验表明该方法不受信号非整周期采样的影响,有效地提高了非整周期采样信号的频率估计精度,改善了LFMCW雷达的测距精度。

To improve the frequency estimation precision of the sampling signals with non-integer period,a phase and frequency matching based frequency estimation method is proposed. Firstly,the windowed autocorrelation of the sampling signals are performed to suppress the influence of non-integer period sampling on autocorrelation. Secondly,the reference signals are generated according to the characteristic that the initial phase of the windowed autocorrelation signal is zero; thus the windowed autocorrelation signals and reference signals have the same initial phase. Finally,the error function between windowed autocorrelation signals and reference signals is constructed according to Cauchy inequation. The error function reflects the matching degree between the windowed autocorrelation signals and reference signals; and the frequency corresponding to the minimum of the error function is the estimated frequency. Calculation verification and LFMCW radar ranging experiment results demonstrate that the proposed method is not affected by non-integer period sampling and effectively improves the frequency estimation precision of the sampling signals with non-integer period,and improves the ranging precision of LFMCW radar effectively.