Implementation of Multi-Frequency Modulation with Trellis Encoding and ViterbiDecoding Using a Digital Signal Processing Board

摘要

Multi-Frequency Modulation has been the topic of several papers at NPS. In pastsystems the majority of time required for the generation of the MFM signal was due to the software routine used to implement the FFT. In this report a Digital Signal Processor was used to reduce the time needed to generate the FFT. The use of Trellis coding and Viterbi decoding on a Digital Signal Processor was also investigated. Assembly language programs for three encoder/decoder systems were developed. The first uses a 16 QAM signal, the second uses a 2/3 rate convolutional encoder and Viterbi decoder and the third uses the V.32 convolutional encoder and a Viterbi decoder.