Per-user outage-constrained power loading technique for robust MISO downlink

A low-complexity robust power loading technique is developed for multiple-input single-output (MISO) downlink systems. The technique uses straightforward probability insights from the second-order statistics of the channel estimation errors to develop a low-complexity iterative algorithm that provides control over the outage probability of each user. In the case of "massive MIMO" channels that harden, the iterations can be approximated in such a way that the computational cost per iteration becomes linear in the number of users. Preliminary simulation results suggest that the proposed technique provides significant improvements in outage performance over conventional techniques.