Coefficient Elimination Algorithm for Low Energy Distributed Arithmetic DCT Architectures

Abstract

An energy aware DCT (Discrete Cosine Transform) architecture based on the distributed arithmetic concept is proposed. Architectures based on the distributed arithmetic concept are inherently low power as they are multiplication free algorithms. One characteristic of the DCT is that upon transformation signal energies are concentrated in only a few coefficients (less than 25%) with the rest (75%) of the coefficients being insignificant and negligible. One can skip the computation of these terms without seriously affecting the output signal quality. Exploiting this idea, we propose a low energy DCT architecture that can achieve 55% savings in the energy dissipation and 28 db in signal quality. In addition, we propose an adaptive energy aware DCT architecture that trades off energy consumption for signal quality. Using this adaptive architecture, we present a study of the effect of coefficient elimination on energy consumption and signal quality.