Cross-layer design for spectrum sensing with selection diversity for cognitive radio systems

In this paper, we propose a new sensor node selection technique to improve spectrum sensing capability by jointly designing with a medium access layer protocol. As cognitive radio (CR) systems have no prior knowledge about the operation of the licensed network, cooperation between physical layer and medium access layer (MAC) is employed in this paper to keep track of operations of sensing nodes. To improve sensing performance, additional sensing nodes are deployed. The status of spectrum sensing at each user and each subband are maintained by finite state machine at the MAC layer. According to the state at CR nodes, the proposed scheme selects the dedicated sensing node for the channel with the best sensing performance. Numerical results show that the performance of the proposed scheme is almost the same as the cooperative spectrum sensing while our proposed scheme requires only one sensing node for the spectrum sensing.