一种改进的自适应格型陷波算法及其收敛性分析

现有自适应格型陷波器中的引入算子取自局部误差信号,在迭代过程收敛后存在陷波频率偏移的问题,影响了滤波的效果.本文对级联格型陷波滤波器的自适应算法进行了讨论,分析了陷波参数估计与引入算子的关系,在推导原算法迭代误差的数学期望方程基础上,提出一种改进的自适应滤波算法.该算法在不增加计算量的前提下,克服了原算法在收敛后存在的陷波频率偏移的不足.仿真结果与理论分析相一致,证实了该算法的收敛性能优于原有的算法.

A Modified Adaptive Algorithm of Lattice Notch Filter and Its Convergence Analysis

The existing adaptive lattice notch filter whose regressor is got from local error signal has a bias of the notch frequency after convergence of iterative procedure,and the effectiveness of filtering is not desired.This paper discusses about adaptive algorithm of cascaded lattice notch filter.Analyzing the relationship between coefficients estimated and regressor,a modified adaptive algorithm is proposed according to the deduced expectation equation of iterative error.Without additional computation,this algorithm has a reduced bias in the estimation of notch frequency,which is exhibited in former algorithms.Simulation results confirm the theoretical analysis and demonstrate the convergence of the algorithm is better than that of former algorithms.