Cooperative Spectrum Sensing and Communication in Cognitive Radio Networks

In cognitive radio systems, secondary users should continuously sense the licensed spectrum in case a primary user starts to transmit. Whether or not the secondary users can sense the spectrum during the secondary communication is an attractive problem. In this paper, we consider a particular wireless cooperative communication system acting as a secondary system, and demonstrate that by exploiting the cooperative property of the cooperative communication, the secondary system dose sensing while communicating. Compared with the conventional periodical sensing scheme, the proposed method achieves better sensing performance without any overhead. The theoretical analysis is given, and the sensing performance of the secondary system is investigated. Simulation results show that the sensing performance of the proposed method is improved significantly as opposed to that of the conventional spectrum sensing.