Optimal decoding of entropy coded memoryless sources over binary symmetric channels

A study was carried out to address the design of an optimal decoder (MAPD), in the maximum a posteriori (MAP) sense, for an entropy coded memoryless source transmitted over a binary symmetric channel (BSC) with channel cross over probability ε. A stream of 40,000 samples of a zero mean, unit variance, Gaussian source, quantized with uniform, N-level quantizers was Huffman encoded and the resulting bit stream was transmitted over a BSC. Experiments were performed for values of N ranging from 128 to 1024 and for four different random error patterns, obtained using a random number generator. The results demonstrate that the MAPD performs better than the HD on an average. A maximum reduction of 2.94% in the bits that are out of synchronization was achieved for the 1024 level quantizer.