基于Rife算法的跳频信号瞬时频率估算方法研究

针对Rife算法在被估计信号频率位于量化频率点附近时估计精度较低的问题,提出一种改进的Rife跳频信号频率估计算法.该算法提出利用频谱细化的方法对信号DFT谱中次大谱线的位置进行搬移,从而使信号频率始终位于其DFT谱中两根最大谱线之间的中心区域.同时为了消除Rife算法在信号信噪比较低时,由于插值方向错误而增大的频率估计误差,提出对被估计信号加窗的方法对算法进行进一步的修正.仿真结果表明该算法的估计精度、抗噪性能和稳定性相比于Rife算法都有所提高.

Research on Instantaneous Frequency Estimation of Frequency-Hopping Signal Based on Rife Algorithm

The performance of Rife algorithm is analyzed and it is pointed out that it has low estimation accura cy when the true frequency is much close to quantized frequency of FFT.In order to solve this problem,an improved Rife algorithm is presented.This algorithm can make the signal frequency always located in the center between the two neighboring discrete frequencies by using zoom FFT technique.Then,in order to elminate the influence of the low SNR on the Rife algorithm,a method to correct the improved Rife algorithm by using the window function for the signal is proposed.Simulation result shows that the improved algorithm has higher esti mation accuracy,stronger anti-noise performance and better stability than Rife algorithm.