Research And Design On Multiband Cognitive Radio Cooperative Model

Cognitive Radio discovers the idle authorized spectrum by sensing the wireless environment, so as to reuse the spectrum resource. The use of cognitive radio can efficiently alleviate the problem of increasingly scarce spectrum resource.Firstly, this paper studies the background and principle of cognitive radio, and investigates the cooperative spectrum sensing and compressive sensing in detail. The part of cooperative spectrum sensing consists of cooperative communication, spectrum sensing, and cooperative sensing. And the part of compressive sensing consists of sparse representation of the signal, design of the measurement matrix, and signal reconstruction.Secondly, on the basis of cognitive radio and cooperative spectrum sensing, this paper establishes a system model of cooperative spectrum sensing, proposes an algorithm of imperfect control channel based cooperative user selection, and analyses the performance. Simulation result shows that, when meeting the ideal false alarm rate requirement, choosing part of the cognitive users with high equivalent probability of detection to perform cooperative spectrum sensing, the performance is similar to the case of all cognitive users. But this method decreases the number of decisions sent to the fusion center, cuts down the time of the fusion center fusing decisions, lessens the accuracy requirement of the threshold, and reduces system consumption.Finally, on the basis of compressive sensing, this paper established a system model of compressive cooperative spectrum sensing, proposes an algorithm of compressive cooperative spectrum sensing based collaborative recovery, and analyses the performance. Simulation result shows that, when every cooperative cognitive user senses part of the channels randomly, it can reach the ideal probability of detection and false alarm rate. Besides, this method alleviates the burden of cognitive user and the fusion center, and reduces system consumption.