2017/10/20 by Truong, Lan V., Tan, Vincent Y. F.
#FOS: Computer and information sciences #Information Theory (cs.IT)
paper · doi:10.48550/arxiv.1710.07419
We consider transmission of discrete memoryless sources (DMSes) across discrete memoryless channels (DMCs) using variable-length lossy source-channel codes with feedback. The reliability function (optimum error exponent) is shown to be equal to max\0, B(1-R(D)/C)\, where R(D) is the rate-distortion function of the source, B is the maximum relative entropy between output distributions of the DMC, and C is the Shannon capacity of the channel. We show that, in this setting and in this asymptotic regime, separate source-channel coding is, in fact, optimal.