Probabilistically constrained robust power allocation in downlink multiuser MISO systems

We consider the problem of robust power control in a downlink system. The base station (BS) is equipped with an antenna array and users have single antennas. The robustness addresses the problem of imperfect channel state information (CSI) at the BS. The CSI mismatch is assumed to be Gaussian. An algorithm for robust power allocation is designed to minimize the total transmit power while simultaneously satisfying predefined users´ quality-of-service targets with certain probabilities. The solution is found to be significantly less conservative comparing to the strategies based on worst-case optimization.