A novel centralized network for sensing spectrum in cognitive radio

Spectrum sensing plays a paramount role in cognitive radio (CR), which is widely agreed to be the most promising method for alleviating the symptom of RF spectral scarcity. In this paper, we first analyze the effects of multipath/shadowing on a CR system. Furthermore, we build models for the primary user system and the CR user system seperately. For the former model, we develop the Possible Conversation Zone to represent the CR cooperative detectable zone. For the latter model, we construct a novel centralized network, called the Spider-Net Sensing Network (SNSN), to implement controllable sensing resolution and reliable sensing while avoiding harmful interference from other CR users. Finally, the numerical results show that our proposed SNSN outperforms one without a grid structure using the same combining scheme.