Cooperative Spectrum Sensing Scheme And Spectrum Sharing Strategy In Heterogeneous Cognitive Network

With the increasing demand of mobile users and the large-scale deployment of new wireless communication networks,network architecture presents the status quo that multiple systems coexist and cover multiple layers of aliasing.The utilization of spectrum resources is very uneven and the problem of shortage of spectrum resources is becoming more and more serious.In the meantime,cognitive radio technology has drawn wide attention in recent years.The dynamic spectrum sharing technology can effectively solve the lack of spectrum resources.Cooperative spectrum sensing mechanism is an important part of cognitive radio technology.The usage of the spectrum sensing results to call spectrum resources property can improve spectrum utilization and meet the increasing spectrum demand of mobile communication services.This paper proposes a dynamic double-threshold cooperative spectrum sensing mechanism based on energy detection to improve the performance of the traditional spectrum sensing mechanism.Since the perceived result obtained by comparing the original energy values at the traditional single energy threshold is unreliable,the double-threshold setting is adopted in this paper,which further needs to process the original energy values located between the two thresholds.Considering the changing channel states,this paper presents a dynamic threshold adjustment strategy based on instantaneous signal to noise ratio to improve the detection probability and perception performance.Based on the results of cooperative spectrum sensing,we design a new spectrum sharing strategy under the scenario of heterogeneous dual-layer networks consisting of macrocells and microcells,in which there are analyses of interference factors to be considered in the macrocell and femtocell heterogeneous double layer network.We propose a sharing scheme that dynamically adjusts macrocell-specific sub-channel ratios based on user distribution.By studying the full-band overlay spectrum sharing strategy,the average data rate and the channel interference of macrocells and microcells are deduced.Therefore,microcell users'spectrum access opportunities are enhanced,interference generated by the system is reduced,and spectrum resources are efficiently utilized.