An optimal cooperative spectrum sensing scheme based on linear coherent MAC under interference temperature constraints

In this paper, we consider a cognitive radio (CR) system in non-ideal fading wireless channels and propose a cooperative spectrum sensing scheme based on coherent multiple access channel (MAC) serving as an alternative way to improve the cooperative spectrum sensing performance. We assume that the gains of the observations and transmission channels are all known which is available since we use standard preamble-aided channel estimation techniques to require channel state information. The key feature of the proposed scheme is that energy of the observations is transmitted by amplify and forward transmission from cognitive users (CUs) to a fusion center (FC) and a linear combiner at FC. Optimal weighting coefficients of the proposed scheme are got by maximizing the detection probability under a target false alarm probability and transmit power constraint. The effectiveness of the proposed scheme is verified by the simulations.