Joint Radio Resource Allocation Algorithms Based On Cooperative Spectrum Sensing In Cognitive Radio

Cognitive Radio(CR),which is proposed to alleviate spectrum resource shortage,adopts the opportunistic spectrum access by admitting secondary user(SU)to utilize the unlicensed spectrum or the licensed spectrum without primary user(PU)to improve the spectrum efficiency.To avoid interference to the normal communication of PU,SU has to sense the status of PU continually.Energy detection has been widely used as an effective spectrum sensing method in CR network,because it doesn't need any prior information of the PU and also owns high reliability.However,the hidden terminal problem caused by multipath fading and shadow effect may decrease the sensing performance greatly.Cooperative spectrum sensing is proposed to overcome this problem by combining the independent sensing information of different SUs locating in different sensing areas and making a final decision in a fusion center.Therefore,this paper is mainly based on the cooperative spectrum sensing(CSS)in cognitive radio and investigates the radio resource allocation algorithms via model formulation,algorithm optimization and simulations.In this paper,CSS cognitive radio system is studied from the aspects of cooperative fairness of SUs,maximization of system energy efficiency and SUs' access when PU is detected busy.Firstly,a joint optimal model of fair CSS and transmission,which can compensate the sensing overhead of cooperative SUs,is proposed to ensure the user fairness.Then,the energy efficiency of cognitive system is defined and analyzed,and a joint optimal energy-efficient CSS and transmission in multi-channel CR is proposed to optimize the radio parameters of sensing and transmission,while the energy-efficient maximization is ensured.Finally,considering the reasonable exploitation of the licensed spectrum when PU is detected busy.A benefit-exchange access mode is proposed and a holistic joint optimal CSS and transmission based on cooperative relay communication in Cognitive Radio is formulated in this paper.When PU is detected busy,it can realize the reasonable utilization of the licensed channel.