Lossy communication of correlated sources over multiple access channels

A new approach to joint source-channel coding is presented in the context of communicating correlated sources over multiple access channels. Similar to the separation architecture, the joint source-channel coding system architecture in this approach is modular, whereby the source encoding and channel decoding operations are decoupled. However, unlike the separation architecture, the same codeword is used for both source coding and channel coding, which allows the resulting coding scheme to achieve the performance of the best known schemes despite its simplicity. In particular, it recovers as special cases previous results on lossless communication of correlated sources over multiple access channels by Cover, El Gamal, and Salehi, distributed lossy source coding by Berger and Tung, and lossy communication of the bivariate Gaussian source over the Gaussian multiple access channel by Lapidoth and Tinguely. The proof of achievability involves a new technique for analyzing the probability of decoding error when the message index depends on the codebook itself. Applications of the new joint source-channel coding system architecture in other settings are also discussed.