Real-time broadcasting over block-fading channels

Broadcast transmission from a base station (BS) to a group of users is studied. It is assumed that the BS receives data at a constant rate and tries to broadcast these messages to the whole set of users within a certain deadline. The channels are assumed to be block fading and independent over blocks and users. Our performance measure is the total rate of received information at the users within the transmission deadline. Three different encoding schemes are proposed, and they are compared with an informed transmitter upper bound in terms of the average total reception rate for a set of users with varying channel qualities. It is shown that no single transmission strategy dominates for all channel settings, and the best broadcasting technique depends on the distribution of the average channel conditions over the users.