Research On Spectrum Sharing Strategy In Utility-based Cognitive Radio Networks

Cognitive radio(CR)technology is an important technology of the future wireless communication(5G).Cognitive radio technologies allow the users who equipped with cognitive devices but without licensed spectrum(Secondary Users,SUs)to access licensed spectrum of primary users(Primary Users,PUs)by sensing the surrounding wireless environment,adjusting their parameters dynamically.On the basis of avoiding incur harmful interference to PUs,this technology can realize spectrum sharing and maximize the spectrum efficiency.Since PUs and SUs are rational but selfish users,based on cooperative relay net-works and heterogeneous networks,to further improve the spectrum usage efficiency and energy efficiency,we analyze the spectrum sharing problem in cognitive radio networks with game theory and auction algorithm in this paper,the main work is as follows:1.The spectrum leasing in cooperative relay cognitive radio networks is studied,the SU acts as a cooperative relay,which results in earlier completion of the primary transmission and the winning of opportunities for secondary transmission.The PU increases its communication quality of service(QoS),decreases energy consumption and obtains pay backs by optimizing the leasing price,while the SU maximizes its throughput,minimizes the energy consumption and fees by optimizing lease time.We formulate this model as a Stackelberg game,and adopt the Stackelberg equilibrium as the optimal strategy.2.Considering the problems of shortage of energy,the energy cooperation problem between the PUs and SUs based on hybrid energy supplies is investigated.In this case,the SU harvesting energy from the RF signal when the PU is transmitting its data.The SU uses the harvested energy largely,and when the harvested energy is too less to support the whole communication process,the SU can use on-grid power supplies to ensure steady transmission.This kind of power supply mode can reduce the energy consumption of fixed power supply effectively,and make up the weakness of unstable energy harvesting.3.In macro-femtocell heterogeneous cognitive radio networks,the problem of data offloading and spectrum sharing are studied,how to stimulate macrocell and femtocell both adopt hybrid access mode is an important issue.Different from most economics models,the sub-channels which turn to idle state from busy state after offloading users are not taken into consideration.In this paper,an incentive mechanism that use spectrum as a reward rather than money is proposed.We propose an auction-based dynamic spectrum sharing strategy,which can make the best use of idle spectrum and improve the utility of macrocell and femtocell.