Research Of Cooperative Spectrum Sensing In Cognitive Radio Networks

Spectrum sensing technology is one of the most important foundations of cognitive radio system. Currently the research in spectrum sensing can be categorized into two aspects:the accuracy and the efficiency of spectrum sensing. This thesis presents the research done in these two aspects based on the cooperative spectrum sensing model. Summary of contents and contributions include:1. A new scheme of cooperative sensing partner selection based on the comparison of Signal Noise Rate (SNR) for narrow spectrum band is proposed, which considering the necessity of cooperation and collaboration gain. Theoretical analysis and simulation suggest the new scheme can improve the detection performance of spectrum sensing and reduce the number of cognitive users involved, thus improves the efficiency of cooperation.2. An optimal multiband cooperative spectrum sensing strategies in cognitive radio networks is studied for cooperative spectrum sensing network based on multiband. An optimization problem is formulated. Determining the decision threshold, the total sensing time and distributing the total sensing time to maximize the throughput of secondary users are studied. The initial non-convex mixed-integer problem is transformed into convex mixed-integer sub-problems, and achieved the optimal solution by the incremental algorithm. Theoretic analysis and relative simulations have been made.3. An optimization problem is formulated based on the tradeoff between sensing reward and sensing overhead. Determining the number of cognitive users, the decision threshold, the total sensing time and distributing the total sensing time to maximize the throughput of cognitive network are studied. Theoretic analysis and computer simulation prove the correctness.