Survey on Different Architectures of DLMS Adaptive Filter

Abstract

ABSTRACT: The LMS Adaptive filter has wide range of applications but it cannot support pipelined operations because of its recursive behaviour. An efficient architecture of Delayed LMS algorithm thus has been proposed that supports pipelining. The paper discuses about the DLMS algorithm and different architectures of DLMS adaptive filter in brief. These architectures concentrates on increasing usable frequency, minimize the adaption delay and area. The comparison between these various architectures based on critical path, hardware elements required is discussed. KEYWORDS: Adaptive Filter, LMS algorithm, DLMS Algorithm, Critical Path, Pipelining. I.INTRODUCTION The adaptive filter itself can adjust its transfer function according to an optimizing algorithm and object can be achieved by the modification of its characteristics. They provide flexibility and accuracy in the field of communication and control. The LMS (Least Mean Square) algorithm is widely used because of its easy calculations and better convergence performance. LMS adaptive filter has wide range of applications in communication and DSP (Digital Signal Processing) such as predictor, system identification, noise cancellation, equalization. However the direct implementation of LMS algorithm has long critical path which is due to the complex inner product computations to obtain the filter outpu