Distributed Detection of Primary Signals in Fading Channels for Cognitive Radio Networks

In this paper, we investigate cooperative sensing schemes to identify primary signals in fading environment for cognitive radio (CR) networks employing energy detectors. We consider a parallel fusion architecture in which all the sensing devices send their quantized sensing information to an access point, which then applies a fusion rule to determine the presence of the primary signal. We assume independent and identically distributed fading at various CR sensing devices. Considering identical binary quantization at the sensing devices, we study the optimal quantization and data fusion scheme. We compare the performance of the optimal binary data fusion scheme based on identical quantizers with the performances of other binary data fusion schemes commonly used in the literature for CR cooperative sensing networks. We further investigate the performance gain that could be obtained by using identical multi- bit quantization at the sensing devices.