On the Capacity of the Fading Broadcast Channel with State Feedback

This paper studies the capacity of the two-user memoryless fading MISO broadcast channel, where the channel states are assumed to be fully known at the destinations but only known strictly causally -state feedback-at the transmitter. We derive an inner and an outer bound on the capacity region of this channel. Numerical results reveal the SNR regimes in which state feedback is beneficial in terms of sum-rate. Our results -in contrast to similar works focusing on degrees of freedom-appears to be the first step toward a better understanding of the advantage of state feedback in moderate SNR regimes.