A Practical Method of Obtaining Constant Convergence-Rates in LMS Adaptive Arrays

This paper shows a practical method of eliminating the old problem of widely-disparate modal convergence rates in LMS (Least-Mean-Squares) adaptive arrays. The method is mathematically based on the Newton-Raphson iteration technique of finding zeros of a function. The practical realization is based on an extension of Compton's improved-feedback adaptive loop. It is shown how this modificationt results in constant and equal modal convergence rates in an adaptive array. The improved algorithm is also compared to Compton's original improved-feedback loop and to a "standard" LMS adaptive array. Preliminary experimental results are also shown to substantiate some of the analysis.