Research On Compressive Spectrum Sensing Technologies Of Cognitive Radio

As the development of wireless communication technologies, the wireless spectrum resource isvery scarce globally. Cognitive radio (CR) technology is an effective solution to handle the problem.Spectrum sensing is a foundation in the cognitive radio technology. The compressed sensingapproach is adopted to attain high-resolution signal recovery at lower than Nyquist sampling rate.This paper studies the following three questions:First, a new cooperative compressive spectrum sensing strategy based on fuzzy decision schemeis investigated. Here, the compressed sensing approach is adopted to recover the signal at a lowsample rate. Based on double threshold energy detection, the fuzzy decision scheme is proposed,and the closed-form expression is given between the detect probability and false alarm probability.Analysis and simulations show that the proposed scheme could improve the sensing performanceeffectively compared with conventional decision scheme.Second, a highly eiffcient cooperative spectrum sensing strategy is proposed to reduce thecommunication overhead. Based on single threshold energy detection and equal gain combination,this strategy uses a smoothing factor contributing to saving the communication overhead.Simulations show that this strategy can not only reduce communication overhead, but also achievealmost the same detection performance with traditional cooperative spectrum sensing scheme.Third, a gradient-based distributed cooperative scheme is proposed in CR-MAHNETs. Theproposed approach is in multi-hop CR-MAHNETs. The approach is based on energy detection.These distributed algorithms converge fast to the globally optimal solutions and have little energyconsumption. Simulation results show the effectiveness of the proposed approach.