Competitive unlicensed spectrum sharing with partial information on slow fading channels

We consider a slow fading multiuser environment with primary and secondary users. The secondary users have only partial knowledge of the channel and are subjected to transmitted power constraints by the primary users. Their communications are intrinsically affected by outage events. We propose and analyze two algorithms for joint rate and power allocation. In one algorithm, the secondary transmitters cooperate to maximizing a common utility function accounting for the total throughput of the network. In a second approach based on a game framework, the secondary users aim at maximizing selfishly their own utilities. The latter approach shows better fairness properties at the expenses of some global performance loss compared to the optimum cooperative approach.