Performance of Spectrum Sensing over Fading Channels and an Energy Efficient Cooperative Spectrum Sensing Scheme for Cognitive Radio

Cognitive Radio (CR) is a radio communications and networking technology that has recently attracted considerable interest from academia as well as industry worldwide. It follows the design philosophy of Dynamic Spectrum Access (DSA) as opposed to a fixed spectrum allocation policy. The enabling technology for CR is spectrum sensing, which is the inference of presence/absence of primary users (PU) in a given spectral band. Spectrum sensing is complicated by the fading effects of wireless channels, which necessitates CRs to collaborate with one another to make sensing results robust. Another aspect that must be considered in practical CR networks is the energy efficiency of the spectrum sensing process, due to the recent emphasis on 'Green Wireless'. This paper first evaluates the performance of spectrum sensing over different fading channels and shows how collaborative sensing improves robustness. Subsequently, the paper considers an improvement to current techniques for energy efficient spectrum sensing by employing techniques from the field of Compressed Sensing (CS).