Research On Spectrum Sensing Algorithms In Cognitive Radio Based On Intelligent Algorithm

As the wireless communication "blood" of the wireless spectrum, it’s non-renewable nature indicates that less available spectrum resources can be used. With the dramatic increase of wireless communications technology and the increasing demand of the spectrum resource, the scarcity of spectrum resources has been an urgent problem. In this context, cognitive radio(CR) has emerged as a key technology of improving the spectrum utilization efficiency via reuse the free spectrum resources to solve the problem. Spectrum sensing, as the core of cognitive radio, has become the focus of the researchers.The traditional algorithms only investigate single user detection that makes the lower performance, after adding collaboration mechanisms greatly improve the spectrum sensing performance. Wideband system, a mainstream systems, is became a hot study. Due to the complexity of the wideband system, the traditional algorithms are difficult to achieve the performance of real-time and reliability requirements, on other hand, wideband spectrum sensing problem is a non-convex problem, which is thus difficult to solve the problem directly, so intelligent optimization method has been propose. Because of is robust and wide adaptability, intelligent optimization method, which is derived from the biological evolution, can be used to solve the non-convex problem. The following are the specific contents of this paper:Firstly, introduced the significance and current situation of cognitive radio, and introduced the spectrum sensing, especially three common spectrum sensing algorithm and cooperative spectrum sensing technology. At the same time, compared the intelligent optimization method with the traditional optimization methods, and introduced the common methods of the intelligent optimization methods as well. Secondly, introduced the basic principles and some related parameters of the particle swarm optimization(PSO). By set up the optimization model, we propose a method which based on the improved PSO to solve the problem of cooperative spectrum sensing. Simulation results show that the improved PSO algorithm can makes the cooperative spectrum sensing effectiveness and superiority. Finally, through the analysis of wideband spectrum sensing system, the wideband spectrum sensing model has been established, and then we propose a method which based on the PSO to solve this problem, and the simulation results show the effectiveness of the PSO algorithm.