Research On Cooperative Spectrum Sensing In Cognitive Radio Networks Based On Credibility

With explosive growth in demand of high rate data service, the wireless spectrum resource scarcity has become increasingly serious. However, the current spectrum use is still based on the static allocation strategy. Because of this strategy, the utilization of the allocated spectrum is very low. Cognitive radio, an opportunistic spectrum access method, which can reuse authorized spectrum, is considered to be the most important scheme to solve this problem. Spectrum sensing is one of the key technologies to ensure the normal application of cognitive radio.The paper focus on the research of cooperative spectrum sensing,the main works are as follows:1. An adaptive cooperative spectrum sensing algorithm based on credibility and SNR is proposed. First, the estimated value of SNR is used to obtain CR users’ initial credibility, and then the adaptive parameter adjustment strategy is utilized to remove abnormal users and high SNR malicious users. Simulation results indicate that the algorithm can improve the detection performance and stability. The Real-time performance and malicious user resistance ability are also better than that of the adaptive cooperative spectrum sensing method and traditional K rank cooperation spectrum sensing algorithm.2. The OFDM signal spectrum sensing in very low SNR is studied, An indirect credibility based cooperative spectrum sensing algorithm is proposed, First, local spectrum sensing is arrived at by applying the Pilot estimation, then parameter adjustment speed control is achieved using the indirect credibility between cognitive users. Simulation result shows that the proposed algorithm can effectively improve the cooperative spectrum sensing performance.