Transmit Power Selection by Cooperative Sensing in Cognitive Radio Networks

In cognitive radio systems, secondary users are allowed to use the spectrum allocated to some primary user if they do not cause harmful interference to the primary user. This is called as a spectrum sharing. In the conventional spectrum sharing, the secondary user senses the spectrum and makes a binary decision: the spectrum is either available or not. In this approach, fixed transmit power has been assumed. Instead of just making a binary decision, we employ a new approach where the allowable maximum transmit power level is selected from the prepared transmit power levels with the constraint on the miss detection probability which guarantees the primary user performance. The proposed approach can extend the area where the secondary user is allowed to use the spectrum with the transmit power selection. Computer simulation results present that the proposed method can improve spectrum utilization.