Yangfan Zhong Fady Alajaji L. Lorne Campbell On the Joint Source-Channel Coding Error Exponent for Discrete Memoryless Systems: Computation and Comparison with Separate Coding http://arxiv.org/abs/cs/0601006 2006 CoRR abs/cs/0601006 db/journals/corr/corr0601.html#abs-cs-0601006 informal publication