WLC39-2: Optimal Stochastic Power Control with Outage Capacity Constraints

With the causal channel state information at the transmitter (CSIT) and the channel statistics in the future, in this paper, we address the power allocation problem to achieve a given information rate with certain probability (i.e., outage rate) for a block Rayleigh-fading channel. In particular, we aim to minimize the total power required for achieving an outage capacity by adaptively and stochastically allocating the transmit power for each block. Using Gaussian approximation, we shall derive the outage probability for a given rate, and then illustrate that the optimization problem is, in general, not convex. To determine the optimal power policy, however, it is shown that the optimization can be solved numerically at affordable complexity. Numerical results demonstrate that the proposed power policy yields significant power reduction compared to an equal-power policy for a given outage rate.