小波基在低压电力线信道有色背景噪声建模中的应用研究

摘要

小波马尔科夫链法可用于低压电力线信道中有色背景噪声的建模,但小波基函数的不同会对噪声的建模精度产生较大影响.基于常用的几种小波基函数对同一组有色背景噪声分别开展小波马尔科夫链仿真建模,并计算了建模前后的功率谱密度及其均方根误差.研究结果表明,Daubecies、Biorthogonal和Haar小波基函数中Daubecies 小波基函数的建模精度较高,Haar小波基次之,Biorthogonal小波的建模效果较差.在这3种小波基函数中,Daubecies小波可选为有色背景噪声进行小波马尔科夫链建模的最佳小波基函数.%The wavelet packet transform and peak typed Markov chain can be used to model the colored background noise for low-voltage power line channels.Different wavelet basis functions have a major impact on the accuracy of noise modeling.Under different wavelet basis functions,the simulated colored background noise is modeled by wavelet packet transform and peak typed Markov chain respectively,and their power spectrum densities before and after modeling are calculated as well as their corresponding root-mean-square errors (RMSE).In the aspect of modeling accuracy,it can be found that the Daubecies wavelet is the best and the Haar wavelet followed.Therefore,the Daubecies wavelet is the best wavelet basis function of the wavelet packet transform and peak typed Markov chain,which can be used to model the colored background noise in low-voltage power line channels.