Research On Cooperative Spectrum Sensing Algorithm For Cognitive Radio Network

The proliferation of wireless communications equipment gradually reduce the amount ofspectrum without license, a lot of spectrum resources are used to support a large number ofnew wireless services. The federal communications commission (FCC) latest test show thatwithin a certain time and space is only15%~85%of the spectrum used by authorized users,that is to say of spectrum utilization rate is quite low. Static spectrum allocation mechanism tosolve the mismatch between and dynamic spectrum utilization way, cognitive radio as a newintelligent wireless communication technology has been raised, to ease the spectrumutilization efficiency under with the contradiction between the growing demand for spectrumresource.Firstly, This paper outlines the basic principles of cognitive radio network, includingrelated concepts, the main ability and key technologies, etc; Second, It introduces the existingspectrum sensing technology in cognitive radio network, comprehensively summarized theprinciple and characteristics of spectrum sensing technology. Three kinds of commonly usedsingle node are analyzed and compared in perceived merits and demerits in the process ofspectrum sensing method, including the matched filtering, energy awareness and perceptioncirculation stationary feature perception; The focus research on the three kinds of typicalcollaborative perception algorithm principle, process and performance characteristics,including based on partition algorithm, logarithmic likelihood ratio algorithm and weightedcollaborative algorithm, and through the simulation analysis to compare the performance ofthe collaborative perception algorithm. Collaborative perception can effectively overcome thesingle node "hidden terminal" perception algorithm caused by the problem o f low probabilityof perception, therefore, has become the research hot spot. Current research of collaborativeperception algorithm the difficulty lies in the selection of fusion decision criterion, judgmentcriteria, including hard decision and soft decision fusion is combined with hard and softdecision. Hard decision criteria include:"OR","AND" and "K" criteria. Due to poor channelconditions, the energy of each user is fuzzy, often there will be more perceived valuedistribution around the threshold method, It is difficult to have clear boundaries, this timeusing hard decision error can be big, soft decision criterion is introduced as a mainstream.Chapter3and chapter4is the research emphasis of this paper. Chapter3analysis of thecurrent three typical collaborative perception algorithm principle, process and performancecharacteristics; Chapter4using the fuzzy integral theory, this paper proposes a new groupingcollaborative spectrum sensing algorithms, Simulation analysis shows that the proposedalgorithm under the condition of the same SNR, detection probability is lower than hard bymistake under the judgment criterion of collaborative awareness and traditional groupcollaboration awareness; Also can be seen in the signal-to-noise ratio SNR equals to-5db, the false detection probability of the algorithm almost to zero. But the computation complexity ofthe algorithm is relatively high, feel for a long time, so the proposed algorithm is suitable forcomputing complexity and the perception time makes no special requirements, but to perceiverequiring higher precision. Finally, the full text of the work is summarized and prospect.