Streaming Transmission over Block Fading Channels with Delay Constraint

Streaming transmission over a block fading channel is studied assuming that the transmitter receives a new message at each channel block at a constant rate, which is fixed by an underlying application. A common deadline is assumed for all the messages, at which point the receiver tries to decode as many messages as possible. Various achievable schemes are proposed and compared with an informed transmitter upper bound in terms of average throughput. It is shown that the adaptive joint encoding (aJE) scheme is asymptotically optimal; that is, it achieves the ergodic capacity as the transmission deadline goes to infinity; and it closely follows the upper bound in the case of a finite transmission deadline. On the other hand, in the presence of multiple receivers with different signal-to-noise ratios (SNR), memoryless transmission (MT), generalized time-sharing (gTS) and superposition transmission (ST) schemes are shown to be more robust than the joint encoding (JE) scheme as they have gradual performance degradation with the decreasing SNR.