An Improved Cooperative Sensing Protocol for Cognitive Radio System

In cognitive radio systems, cooperative spectrum sensing is employed to detect the presence of primary user quickly and accurately. In this paper, we propose a new TDMA cooperation protocol to improve the overall agility and spectrum efficiency compared to the existing protocols. By allowing the cognitive users operating in the same band to cooperate, the detection time is reduced and thus the average number of slots taken for detection is decreased under the new scheme. In particular, it decreases the average detection time per slot. We consider a two-user cognitive radio network and show how the inherent asymmetry in the network can be exploited to increase the agility. Numerical results illustrate that this cooperative relay sensing scheme can improve the detection probability, and the spectrum efficiency of the network.