Abstract
In this paper, we consider a spectrum sharing cognitive radio system with ratio selection using a mean value-based power allocation strategy. We first provide the exact statistics in terms of probability density function and cumulative density function of the secondary channel gain as well as of the interference channel gain. These statistics are then used to derive exact closed form expression of the secondary outage probability. Furthermore, asymptotical analysis is derived and generalized diversity gain is deduced. We validate our analysis with simulation results in a Rayleigh fading environment.