Design of a faithful LNS interpolator

Abstract

A design is given for a quadratic interpolator needed by the logarithmic number system (LNS). Unlike previous LNS designs that have attempted to produce results consistently better than a floating-paint representation of the same word size (32 bits), the design goal is to minimize memory requirements and system complexity, at the expense of a slight increase in approximation error. Simulation results have shown this goal causes only a modest impact on overall accuracy, but the memory savings are significant. Despite a slight increase in error compared to prior LNS implementations, on average, the error is still less than conventional number representations satisfying the IEEE-754 standard. Proposed applications for the interpolator include multimedia, signal processing, graphics and reconfigurable computing.