The Spectrum Sensing Allocation Algorithm In Cognitive Radio And Its FPGA Simulation Implementation

With the development of wireless communication technology,the demand for spectrum resources for various new services has been increasing.However,the allocated spectrum resources account for most of the limited total spectrum resources,which has become a major bottleneck for the continued development of wireless communications.The proposal of cognitive radio is the key to changing this dilemma.It allows unauthorized users to perceive channel conditions and have the opportunity to access the spectrum,which greatly improves the utilization of the spectrum.Firstly,the article describes the background and definition of cognitive radio,then introduces the research status of spectrum sensing and spectrum allocation technology,and expounds several typical algorithms in the two technologies.Secondly,the compressed sensing theory was introduced into traditional energy detection for the limitation of higher frequency signals under Nyquist's theorem.The focus of spectrum sensing is whether there is a signal in the frequency band,while not the signal itself.Also,the accuracy of signal reconstruction will greatly affect the detection performance.Therefore,the article performs non-reconstructed spectrum sensing on the frequency band.Based on the limitations of single-user perception under a single threshold and the lack of multi-user cooperative detection,the double threshold and D-S evidence theory were combined.Each user perceives the results in turn,and selects different fusion strategies for different results,the calculation and fusion of the trust is also selective.It is not necessary to calculate the trust when a user falls within the double threshold interval.In this way,the calculation complexity based on D-S evidence theory is greatly reduced.Then,for the problem that the allocation time is too long and the total benefit of the system is not ideal of the CSGC spectrum allocation model in traditional graph coloring,this article proposed a parallel allocation algorithm that considers the difference in benefits.Assuming that each frequency band is orthogonal to each other,and the allocation does not affect each other,the entire large picture can be decomposed into multiple sub-pictures with a number of spectrums.Coloring the multiple sub-pictures separately can effectively reduce the allocation time.In addition to considering the benefit value of each user,the user benefit difference that will cause interference with the assigned users was also considered,so that the spectrum benefit of the system is improved.Finally,to promote the physical process of spectrum sensing based on compressed sensing,the FPGA simulation platform was also used to verify the simulation besides the using of Matlab.The comparison with the initial prepared data shows that the simulation results are ideal.