改进间接滤波噪声抵消算法在VLF中的应用

Application of improved indirect filter noise cancellation

一般而言,自适应滤波算法在信号通信中被广泛应用于降噪,其主要功能是从含噪信号中直接恢复出有用信号,达到提升信噪比增益的效果。但对于信噪比很微弱的信号,往往因为期望信号微弱而导致滤波器系数偏差较大,此方法往往无法恢复出理想的降噪信号。为解决上述问题,采用并改进原有的间接滤波算法,利用厄米特二次型减少计算量,结合小波变换算法提出一种新型的间接滤波算法,搭建垂直双通道的天线接收模型,以信干噪比增益为主要指标对算法性能进行评价。

Generally speaking,adaptive filtering algorithm is widely used in signal communication to reduce noise.Its main function is to recover useful signals directly from noisy signals,so as to improve the SNR gain.However,for the signal with very low SNR,the filter coefficient deviation is often large because the expected signal is weak,and this method is often unable to recover the ideal noise reduction signal.In order to solve the above problems,the original indirect filtering algorithm is adopted and improved,and the Hermite quadratic form is used to reduce the calculation amount.A new indirect filtering algorithm is proposed based on the wavelet transform algorithm.A vertical dual channel antenna receiving model is built,and the performance of the algorithm is evaluated with the signal to noise ratio gain as the main index.