This paper studies an almost-lossless source-channel coding scheme in which source messages are assigned to different classes and encoded with a channel code that depends on the class index. The code performance is analyzed by means of random-coding error exponents and validated by simulation of a low-complexity implementation using existing source and channel codes. While each class code can be seen as a concatenation of a source code and a channel code, the overall performance improves on that of separate source-channel coding and approaches that of joint source-channel coding when the number of classes increases.

This work was supported in part by the European Research Council under Grant 259663, in part by the Spanish Ministry of Economy and Competitiveness under Grant FPDI-2013-18602, Grant RYC-2011-08150, Grant TEC2012-38800-C03-03, and Grant TEC2013-41718-R, and in part by the European Union’s 7th Framework Programme under Grant 303633 and Grant 329837.