Research Of Spectrum Sensing Technology Based On Cognitive Radio

As one of the key technologies in cognitive radio, spectrum sensing is received more and more attention. By further studying the background of cognitive radio system, spectrum sensing technology is researched deeply in this paper. The research mainly includes two aspects:one is to study local spectrum sensing; the other is about fusion arithmetic of cooperative spectrum sensing.Firstly this thesis introduces the context and concept of cognitive radio, the key technologies of cognitive radio, and the research status at home and abroad on cognitive radio. Secondly, the technology of spectrum sensing is presented mainly through the concept of spectrum sensing, the study status at home and abroad, and some classical spectrum sensing ways. Furthermore, some defects in the research of spectrum sensing technology at present are analyzed in depth.Firstly, for the local spectrum sensing, the energy sensing scheme is studied by means of exploiting the cyclic prefix of an OFDM (orthogonal frequency-division multiplexing) symbol to improve the probability of detection in this thesis. Moreover, the optimal sensing time is analyzed in detail based on the simulation. Secondly, for the purpose of maximizing the aggregate throughput of cognitive radio, a multi-band joint sensing scheme is applied to an OFDM-based cognitive radio system. And genetic algorithm is proposed to deal with the optimization problem in order to greatly improve the aggregate throughput.For cooperative sensing, the tug-of-war-based cooperative spectrum sensing is proposed on the basis of the detailed simulation analysis of classical fusion rules in traditional cooperation spectrum sensing. Considering practical wireless environment and defects of present fusion rule, this scheme fully exploits the spatial diversity by employing the reliability factor obtained from the signal-to-noise-ratio to weigh the local decision of cognitive radio. Then, tug-of-war rule is simulated to effectively fuse local information. The sufficient simulations demonstrate that the tug-of-war-based cooperative spectrum sensing can be achieved...