基于分数阶傅里叶变换的时延和频率偏移联合估计方法

Joint Time Delay and Frequency Offset Estimation Based on Fractional Fourier Transform

针对传统相关运算对时延和频移进行联合估计计算复杂度高的缺陷,提出一种基于分数阶傅里叶变换的时延和频移联合估计方法。该方法利用信号的时延和频偏变换到分数域表现为分数域谱位置的平移特性,通过在不同的分数域利用最小均方误差准则来获得分数域谱位置的偏移量来进行联合估计。该方法不局限于仅适用于Chirp信号,对其它类型的信号同样适用。且与传统相关估计法相比,具有简洁、高效的特点。计算机仿真结果表明,该方法是有效的。

Because of the high computational complexity of the traditional correlation method on the joint time delay and frequency offset estimation,a new joint estimation method is proposed based on the fractional Fourier transform.This method uses the character that a signal with time delay and frequency offset bring about spectra shift when transformed into the fractional Fourier domain.By using minimum mean square error criterion in different fractional Fourier domain,the spectra shift can be obtained for joint estimation.This method is not limited to Chirp signal,but also applicable to other types of signals.Compared with the traditional correlation method,the proposed method is simple and of high efficiency.The simulation results show its effectiveness.