Distributed resource allocation in MIMO OFDMA networks with statistical CSIT

This paper addresses the margin adaptive (MA) problem in MIMO OFDMA multi-cell networks, when the transmitter only has statistical channel state information. Resource allocation is distributed within each base station. A distributed convergence criterion for power control is determined and included within iterative power allocation. An approximate analytical expression is obtained for the outage capacity, as a function of the SNR and of the outage probability. It turns the MA problem into a convex optimization problem, and is valid at practical SNR and outage capacity values, for several antenna configurations. The proposed method avoids power divergence situations at any load, and is consequently more efficient than iterative water-filling to solve the MA problem.