Research On Spectrum Sensing Technology Based On Feature Detection In Cognitive Radio

In order to solve the problem of the current shortage of spectrum resources,the concept of cognitive radio emerged.Spectrum sensing is the primary and key technology of cognitive radio.According to the different number of cognitive users participating in spectrum sensing,spectrum sensing can be divided into single-user spectrum sensing algorithms and cooperative detection.The cognitive users in cooperative detection need to perform single-node spectrum sensing,so the research on single-node spectrum sensing algorithm has a wider application significance.For the problem that energy detection is susceptible to noise under low signal-to-noise ratio,combined with the characteristics of the received signal,this paper proposes the following two improved spectrum sensing algorithms based on the features of energy detection and received signals.1.This paper proposes an improved algorithm based on coefficient of variation and energy detection(abbreviated as SCVED),uses the coefficient of variation of the received signal to correct the energy detection result,and obtains the final result of the mixture.That is,after the energy detection,if the detection energy of the signal energy is within a certain range and the variation coefficient between the received signals is less than the preset threshold value,it is determined that the target frequency band has been occupied by the primary user.The simulation results show that the proposed method can greatly improve the detection accuracy of cognitive spectrum users while ensuring low algorithm complexity.2.Using the difference correlation between signals,a new method of discrimination is introduced between two thresholds,and a joint detection algorithm based on signal difference and energy detection is proposed(abbreviated as difference energy detection).In addition,in the actual communication,the noise is not invariable,and the threshold of detection related to this should also change accordingly.In the difference energy detection,an adaptive dual-threshold strategy is added.The algorithm not only considers the impact of noise on system performance,but also effectively solves the inability of conventional dual-threshold algorithm to perform effective detection.The simulation results show that the difference energy detection can effectively improve the spectrum sensing performance of the system while ensuring the low complexity of the algorithm.In addition,the simulation compares the performance of the differential energy detection and the SCVED algorithm.The experimental results show that the performance of the differential energy detection is slightly higher than the performance of the SCVED algorithm,but the effect is not obvious,and there is no significant improvement.At the same time,the differential energy detection is more complex than the SCVED algorithm.In summary,the SCVED algorithm has more extensive application significance.