Error Exponents for Joint Source-Channel Coding With Side Information

In this paper, we study upper and lower bounds on the error exponents for joint source-channel coding with decoder side-information. The results in the paper are nontrivial extensions of Csiszár´s classical paper “Joint Source-Channel Error Exponent”, Problems of Control and Information Theory, 1980. Unlike the joint source-channel coding result in Csiszár´s paper, it is not obvious whether the lower bound and the upper bound are equivalent even if the channel coding error exponent is known. For a class of channels, including symmetric channels, we apply a game-theoretic result to establish the existence of a saddle point and, hence, prove that the lower and upper bounds are the same if the channel coding error exponent is known. More interestingly, we show that encoder side-information does not increase the error exponents in this case.