On optimal block Markov coding schemes for multiple-access channel with feedback

Finding the capacity of multi-terminal communication systems is a challenging problem. The exact capacity region is known for only a few cases (e.g., multiple-access channels); in most other cases we either have lower and upper bounds on the capacity region (e.g., broadcast channel and relay channels), or know the shape of the capacity region for the high SNR regime (e.g., interference channel). Block Markov coding schemes are a family of coding schemes that are used to determine achievable lower bounds of the capacity region, e.g., for multiple access channels (MAC) with feedback, broadcast channels with feedback , and relay channels.