Communication plays a vital role in every phase of our life. Its development has shrunk the world into a smaller place to live in. Every face of the globe is accessible as a result of the numerous inventions in the field of communications. The communication channel is subject to various interferences like fading, bursts which threaten reliable reception of data. The use of an appropriate and robust coding technique helps to minimize the adverse effects of channel noise. The Viterbi algorithm (VA) is an optimal method in decoding convolutional codes. By using this algorithm as the constraint length increases the accuracy in decoding the data improves. In this book the various techniques, for optimizing the Viterbi algorithm is analyzed for better BER and SNR at various constraint lengths.