Spatially distributed energy-based opportunistic cooperative spectrum sensing in Cognitive Radio Networks

Cognitive Radio Networks (CRN), as a promising technology to increase the underutilized fixed allocated spectrum usage, encounters many new practical challenges. Spectrum sensing is one of the key functionalities in CRN. Spatially distributed cooperative spectrum sensing can effectively solve the hidden primary user problem. However, the number of CRs in the cooperation is dynamically changing over time. We study the impact of this dynamic on the spatially distributed cooperative spectrum sensing performance. The dynamic performances are analyzed. The CRN fusion center does lose its sensing performance significantly if the CRN system size is limited too aggressively due to the dynamic spectrum management concerns. Hence, CRN not only is required to dynamically adapt to its surrounding environment but also has to adapt the corresponding sensing parameters due to the dynamic size aspect of the system. The closed-form performance expressions obtained in this paper provide the analytically tractable framework for efficient system design optimization.