Abstract

The Viterbi algorithm is known to provide an efficient method for the maximum likelihood decoding of convolutional codes. In this thesis, a design and FPGA implementation of a Viterbi decoder with a constraint length of 9 and code rate of 1/2 is presented. In this design, a novel systolic array architecture with time multiplexing, arithmetic pipelining and clock-to-data skews tolerance is developed. Further, by modifying this Viterbi algorithm, an adaptive Viterbi algorithm that is based on strongly-connected trellis decoding is proposed. Using the proposed adaptive algorithm, a design and FPGA implementation of a low-power adaptive Viterbi decoder with a constraint length of 9 and code rate of 1/2 is presented. The systolic array-based architecture used in this adaptive Viterbi decoder is a modified version of the architecture used for the non-adaptive Viterbi decoder in that the latter is modified to include the modules, which are needed for generating the survivor information and for eliminating the spurious toggles in the adaptive Viterbi decoding process.