A high-speed FIR adaptive filter architecture using a modified delayed LMS algorithm

In this paper, we present a modified delayed least means square (DLMS) adaptive algorithm to achieve lower adaptation-delay. Besides, we have proposed an efficient pipelined architecture for the implementation of this adaptive filter. We have shown that the proposed DLMS adaptive filter can be implemented by a pipelined inner-product computation unit for calculation of feedback error, and a pipelined weight-update unit consisting of N parallel multiply accumulators, for filter order N. From the synthesis results we find that the existing direct-form structure of [8] involves nearly 50% more area-delay product (ADP) and nearly 74% more energy per sample (EPS) than the proposed one, in average, for filter orders N = 8,16 and 32. The best of the existing systolic structures [7], similarly, involves nearly 43% more ADP and nearly 35% higher EPS than the proposed one for the same filter orders.