Distributed Arithmetic based Low-Power LMS Adaptive FIR Filter Design

Abstract

filtering forms a significant class of DSP algorithms employed in several hand held mobile devices for applications like echo cancellation, signal de-noising, and channel equalization. This paper presents a different pipelined architecture for low-power implementation of Adaptive filter based on distributed arithmetic (DA). The traditional adder- based shift accumulation for Distributed Arithmetic based computation of inner-product is swapped by conditional signed carry-save accumulation. A fast bit clock is employed only for carry-save accumulation which results in reduction of power consumption in the proposed design, while use of a much slower bit clock is used for rest of the operations. It contains the smaller Look-Up Table (LUT), same quantity of multiplexers and almost half the number of adders in comparison to the existing Distributed Arithmetic-based design. By changing the inner block, a reduction in power consumption is aimed at. So the previous DA-based adaptive filter in average for filter lengths N=4 and N=16 have been implemented.