The New Variable Step Size LMS Adaptive Filtering Algorithm for Low SNR

In order to improve the existing variable step size of filtering performance in low SNR environment,the paper puts forward a new variable step size LMS adaptive filtering algorithm.The algorithm combines the relative value estimation error that is added the compensation term and the former pace to regulate the step size,which can improve the capability of resisting noise and convergence speed.It replaces the fixed step size range restriction by dynamic change restriction,which makes the step change tends to be smoother and reduces system offset errors.Iterative formula of the weight vector is updated at the same time so as to improve the input range of the algorithm.Both from the theoretical analysis and computer simulation we can see that the new algorithm has greatly improve compared with existing variable step size algorithms and the standard LMS algorithm,in the case of low SNR convergence rate,noise immunity,steady-state offset noise,it proves that the proposed algorithm is effective and feasible.