基于改进DFT相位差的正弦波频率估计

摘要

The frequency offset sensitivity problem of discrete Fourier transform ( DFT ) phase difference method in sinusoid wave frequency estimation is studied. An improved DFT phase difference frequency esti-mation method is presented. Firstly,the mean-squared error( MSE) of DFT phase difference method is de-duced. And then,an improved DFT phase difference frequency estimation method based on Rife interpola-tion is proposed. The improved method has well solved the problem of sensitivity to frequency offset. The computer simulation results indicate that the improved method has higher estimation accuracy in any fre-quency offset,and its estimation performance is close to Cramer-Rao lower bound( CRLB) .%针对基于离散傅里叶变换( DFT)相位差的正弦波频率估计方法对频偏敏感的问题，提出了一种改进DFT相位差频率估计方法。首先推导了DFT相位差法频率估计的均方误差，然后提出了基于Rife插值的改进DFT相位差频率估计方法，较好地解决了正弦波频率估计对频偏敏感的问题。仿真实验结果表明，改进方法在各种频偏下均能取得较高的估计精度，估计性能接近克拉美罗限( CRLB)。