Abstract:

 Cognitive radio (CR) is viewed as a novel approach for improving utilization of the precious radio spectrum. This paper first reviews the background and concepts of CR, and then investigates energydetection based spectrum sensing by focusing on the spectrum sensing function. To deal with the problem of local sensing characteristic in wireless signal detections in the energy detection process, a distributed M-cooperative detection scheme is presented. Analytical detection probability based on the “OR” rule is presented. Both simulation and the analytical results indicate that, with a small tradeoff between detection probability and false alarm probability, the scheme significantly improves the spectrum sensing ability under low SNR.

Key words: cognitive radio （CR）; spectrum sensing; energy detection; cooperative detection