Improved differential coefficients-based low power FIR filters. Part I. Fundamentals

This paper and its companion paper (entitled Part II - algorithm) together present techniques for low power realization of finite impulse response (FIR) filters using improved differential coefficients method (DCM). This paper presents the necessary foundation and terminology of the DCM. The companion paper describes our algorithm and presents design examples. In contrast to the conventional DCM that is formulated at the algorithm-level, our method is formulated at the architecture-level using dedicated shift-and-add-based coefficient multipliers in order to achieve considerable hardware reduction. By employing a differential coefficient-partitioning algorithm (DCPA), we show that the number of full adders and the net memory needed to implement the coefficient multipliers can be significantly reduced. The proposed method is combined with common subexpression elimination method for further reduction of complexity. Experimental results show the average reductions of full adder, memory and energy dissipated achieved by our method over the DCM are 40%, 35% and 50% respectively