基于压缩感知和循环谱理论的信号载频估计方法

Signal carrier frequency estimation based on compressed sensing and cyclic spectrum theory

为实现在低信噪比的情况下对载频进行参数估计,提出了一种算法。首先,根据循环谱理论计算出信号的循环谱;然后,采用压缩感知的方法重新构造信号的循环谱切面;最后,根据信号循环谱切面中的离散谱线位置与信号的载频的关系采用平均法来计算载波频率。数值仿真显示在信号稀疏度较高的情况下,对载波频率的估计精度能控制在103Hz以下。在低信噪比的情况下,该算法能够有效地实现对信号载频的估计,在工程上具有一定的实用价值。

Parameters estimation of the modulated signal,such as carrier frequency ,symbol rate,etc.,is the precondition for signal modulation recognition.This paper proposed the algorithm to realize the parameter estimation of the carrier frequency under the condition of low SNR.Firstly,the algorithm calculated the cyclic spectrum of the signal based on the cyclic spectrum theory.Then,it rebuilt the cyclic spectrum of the signal by the compressed sensing method.Finally,it calculated the carrier frequency using the average method according to the relationship between the position of the discrete spectral line in the signal cycle spectrum and the carrier frequency of the signal.The simulation results show that the estimation accuracy of carrier frequency can be controlled below 10 3 Hz under the condition of high signal sparsity.In the low SNR environment,the algorithm can effectively estimate the carrier frequency of the signal,which has certain practical value in engineering.