Alpha稳定分布下基于RHMy滤波的MQAM信号码元速率估计方法

Symbol Rate Estimation of MQAM Signal Based on RHMy Filtering under Alpha Stable Noise

针对Alpha稳定分布噪声环境下,传统的MQAM信号码元速率估计方法性能恶化甚至完全失效的问题,本文结合了改进的M-filter类与小波变换法的优点,提出一种基于递归混合Myriad滤波(Recursive Hybrid Myriad filter,RHMy)的高阶消失矩二次小波变换法对MQAM信号进行码元速率估计。首先采用RHMy滤波充分抑制噪声中的脉冲成分,再采用高阶消失矩小波估计码元速率。仿真结果表明,在Alpha稳定分布噪声环境中,相比于多尺度Haar小波变换法、分数低阶循环谱法与基于加权Myriad滤波(Weighted Myriad filter,WMy)的小波变换法,该方法有效的提高了低广义信噪比下的估计精度,在不同的脉冲噪声条件下具有较好的鲁棒性。

Aiming at the problem that the performance of traditional MQAM signals symbol rate estimation method is deteriorating or even completely invalid under Alpha stable noise environment. According to the combination of the advantages of M-filter class and wavelet transform,a high-order vanishing-moment quadratic wavelet transform method based on Recursive Hybrid Myriad filter（RHMy） is proposed in this paper. Firstly,the RHMy filter is used to suppress the impulse noise of the receiver signals sufficiently,and then the high-order evanescent moment wavelet is used to estimate the symbol rate.Compared with the the multi-scale Haar wavelet estimation method,the fractional low-order cyclic spectrum estimation method and the Weighted Myriad-based wavelet transform method,The simulation results show that the proposed method can effectively improve the estimation accuracy under low generalized signal-to-noise ratio in the Alpha stable distributed noise environment and even under different Alpha values the proposed method also has good robustness.