On the sum capacity of multiaccess block-fading channels with individual side information

We consider the problem of finding optimal, fair and distributed power-rate strategies to achieve the sum capacity of the Gaussian multiple-access block-fading channel. The transmitters have access to only their own fading coefficients, while the receiver has access to all of the fading coefficients. We propose a distributed strategy called the `midpoint' strategy which is optimal when the system cannot tolerate outage. In addition, we demonstrate a successive decoding scheme that can achieve this maximal sum-rate. In presence of outage, we show that the strategies based on a single threshold are suboptimal.