The invention provides a self-adaptive downlink power control scheme for OFDMA-based wireless cellular networks suitable for noise-limited environments. Downlink power levels are assigned in a distributed manner in the absence of any requirement for coordination or cooperation between cells. Distributed assignment allows for more optimal usage of the available transmit power at the base stations and more complete exploitation of the flexibility of frequency domain scheduling. In one embodiment, base stations in a cellular network service mobile user equipment within the respective base station coverage areas, and categorize the user equipment in a plurality of power levels according to certain criteria in accordance with such factors as channel experience and quality. A load-balancing self-adjustment mechanism allows automatic balancing of the load between different power levels.