THE IMPLEMENTATION OF AN IRREGULAR VITERBI TRELLIS DECODER

Abstract

The Viterbi algorithm has uses for both the decoding of convolutional codes and the detection of signals distorted by intersymbol interference (ISI). The operation of these processes is characterized by a trellis. An ARTM Tier-1 space-time coded telemetry receiver required the use of an irregular Viterbi trellis decoder to solve the dual antenna problem. The nature of the solution requires the trellis to deviate from conventional trellis structure and become time-varying. This paper explores the architectural challenges of such a trellis and presents a solution using a modified systolic array allowing the trellis to be realized in hardware.