Optimal strategies for dynamic joint source-channel coding with feedback

The optimal strategy for dynamic joint source-channel coding with feedback was recently shown to be a simple mapping between the source symbols and channel inputs, where the mapping only depends on the decoder's posterior belief about the source. In this work, we derive the optimal joint source-channel coding strategies for two specific channels - binary erasure channels and Z-channels. It is found that the mappings required for the optimal strategies and the way they are used vary significantly with the channel cost of transmission.