A general block-based approach to joint source-channel coding for channels with feedback

Application of joint source-channel coding in heterogeneous multimedia environments demands general adaptive source-channel approaches suitable for a wide variety of source coding standards, channel coders, and variable channel conditions. We develop a general approach for joint source-channel matching based on parametric models for source and channel coders that capture the key characteristics of these coders with respect to source-channel matching. We exploit the flexibility of these coders through the models to obtain an adaptive approach that reconfigures the source-channel system to match time-varying channels. We formulate source-channel matching as an optimization problem by writing the end-to-end performance of the system in terms of the source-channel parameters and including the system resource constraints. We solve the optimization problem for various source-channel combinations to obtain algorithms that determine the optimal source-channel parameters. Our simulations indicate that it may be possible to obtain nearly all of the benefits of joint source-channel optimization by matching existing source and channel coding standards using the simple and general approach we propose.