Streaming data over fading wireless channels: The diversity-multiplexing tradeoff

We study delay constrained sequential streaming over block fading channels. The transmitter observes a stream of messages, one message in each coherence block, and the receiver needs to output a sequence of messages, each with a fixed delay of T coherence blocks. We characterize the associated diversity-multiplexing tradeoff (DMT) for this model. The proposed coding scheme involves a semi-infinite random Gaussian tree-code and a sequential decision directed decoder. The converse applies an outage amplification argument that exploits the delay constraint to amplify the error event associated with a single message to an entire sequence of messages.