International Journal of Computer Applications
In this paper, a transmit power control scheme for a Cognitive Radio System (CRS) in a Rayleigh fading channel based on the location information of primary user is proposed. The situation where Primary User (PU) i.e. licensed user share the spectrum with Secondary User (SU) i.e. cognitive radio have been considered. First a mathematical model for probability of detection as a function of distance between PU transmitter and SU transmitter is developed. The mathematical model takes into account multiple antennas at SUs and uses Energy Detection (ED) with Selective Combining (SC) scheme.