Research On Cooperative Spectrum Sensing Technology In Cognitive Radio

Cognitive Radio (CR) technology is a new revolutionary mode of information communication. How exactly to find―spectrum hole‖and the rational use of the discovery of―spectrum hole‖capability as its core idea. An application of cognitive radio technology can take advantage of detecting―spectrum hole‖, in order to improve spectrum utilization. Spectrum sensing technology is the key integrant in Cognitive Radio. This paper carries comprehensive study on how to improve the detection performance of spectrum sensing technology.The paper used for the irrationality of the spectrum currently leads an emerging technology—cognitive radio technology, first, mainly introduces the research background and significance and look back on the home and abroad of cognitive radio. Second, mainly introduces spectrum sensing technology, it divided into local spectrum technology and cooperative spectrum sensing technology. To the local spectrum technology, several detection methods are introduced and the advantages and disadvantages of these detection methods are also concluded. Focus on the energy detection method and dual-threshold detection method, respectively, in AWGN and Rayleigh fading channels for performance simulation. In practice, the higher the detection probability, the more it can improve the spectrum utilization; false alarm probability is lower, the smaller the interference to authorized users. However, due to cognitive user conditions by internal hardware, plus outside the complex wireless environment, such as shadows, multi-path and other unfavorable factors. The local spectrum sensing technology can not meet the above performance indicators. Put forth a cooperative spectrum sensing technology. Based on cooperative spectrum sensing technology, mainly introduces a centralized cooperative detection、distributed cooperative detection and information integration. Focus on based on D ? S evidence theory and based on data fusion weighted cooperative spectrum sensing algorithm. Although the cooperative spectrum sensing technology can avoid cognitive user‘s interference to authorized users and reduce cost of cognitive user equipment. But this can not meet the needs of practical application. Therefore, this paper proposes a double threshold detection with channel selective method. The basic idea is that the spectrum sensor selects the channel that observes the maximum instantaneous SNR in the sensing channel to perform spectrum sensing for transmitting data. Aim to achieve instantaneous sensing channel detection probability larger, to improve spectrum utilization. This is to solve the spectral efficiency of cognitive radio technology a basic idea‘s achieve.