Determining of convergent threshold and step-size for lms and normalized lms algorithm

Based on eigenvalue distributing of input signal, the convergent necessary, condi-tions for LMS and Normalized LMS(NLMS) algorithm are again researched through the accu-rate analysis of the misadjustment. To avoid blindness for applying LMS and NLMS algorithm, the convergent threshold and the simple adaptive calculating formula for the step-size of them are proposed. The influence of eigenvalue distributing of input signal and order of filter on the threshold of step-size is also analyzed. Compared with an existing algorithm, the characters of lower computational complexity, practicality and stronger adaptive are shown and the satisfied misadjustment is achieved by adopting the presented method for calculating the step-size.