1. A method for allocating user transmission rates in a communication system that is adapted to permit the users to transmit data simultaneously via shared frequency and spatial resources, the method comprising: while maintaining the transmission rates of the users to at least a minimum user transmission rate to provide an expected minimum quality of communication for each of the users, incrementally adjusting the transmission rates of the users by iteratively changing the transmission rate of each user as a function of a resulting vector of transmit powers ensuing from the incremental adjustment of the transmission rate, a degree of transmission-rate-allocation unfairness relative to the transmission rates of all the users, and a power-based selection criteria.