One major purpose of this project is to study mathematical methods of modeling the actual tranmission data so that several parameters of a model can capture the essence of the statistical performance of data transmission on a real channel. This model when verified to be an accurate representation could then be used compactly in the computer to simulate the behavior of the real channel or to evaluate the performance of new codes or modems. Using a model rather than the real channel results in great savings of resources. In Part I of this report the findings in this aspect of the project are summarized. Another major objective of this project is to evaluate the various classes of codes against the model as well as real data from the channel. The aim here is to determine the relative merits of these classes of codes for the improvement of transmission accuracy. Work in this area is reported in Part II of this document. The third major goal of this project is the investigation ot the Viterbi decoding algorithm. Viterbi decoding is a maximum likelihood decoding algorithm for channels without memory.