Design and implementation of RNS-based adaptive filters

Abstract

This paper presents the residue number system (RNS) implementation of reduced complexity and high performance adaptive FIR filters on Altera APEX20K field-programmable logic (FPL) devices. Index arithmetic over Galois fields along with a selection of a small wordwidth modulus set are keys for attaining low-complexity and high-throughput. The replacement of a classical modulo adder tree by a binary adder with extended precision followed by a single modulo reduction stage improved area requirements by 10% for a 32-tap FIR filter. A block LMS (BLMS) implementation was preferred for the update of the adaptive FIR filter coefficients. RNS-FPL merged filters demonstrated its superiority when compared to 2C (two's complement) filters, being about 65% faster and requiring fewer logic elements for most study cases. © Springer-Verlag Berlin Heidelberg 2003.