Based On Cognitive Radio Spectrum Sharing Algorithm Research

Spectrum scarcity is becoming a severe problem in recent years, with the dramaticdevelopment of wireless services and networks. The concept of cognitive radio (orsecondary spectrum access) is currently under investigation as a promising paradigm toachieve efficient use of the frequency resource by allowing the spectrum sharing oflicensed (primary) and unlicensed (secondary) users in the same spectrum bandwidth.Dynamic spectrum leasing as a new paradigm in spectrum sharing can greatly enhancethe spectrum efficiency and encourage more flexible services in the spectrum market. Inthe dynamic spectrum leasing framework, the primary users are allowed to proactivelymanage the amount of secondary activity in their licensed spectrum band, which isdifferent from previous work related to spectrum sharing. In cognitive radio network,cooperation between primary and secondary users can enhance the spectrum leasing andeventually improve each network’s performance. Thus, In this thesis we propose andstudy a new spectrum leasing model in which a primary user leases its bandwidth orpart of its bandwidth for a fraction of time to a network of secondary user in exchangefor its cooperation.In traditional spectrum leasing model, the cooperative SUs use higher power totransmit their own signal but a lower power to relay the signal of primary user. On theother hand, many research can be characterized by a model with one PU and multipleSUs, There are also many works considering multiple PUs and one SU. The resultsfrom these works are either in favor of PUs or in favor of SUs. These works didn’tconsider the the problem from the global perspective.In order to overcome these shortcomings, in this thesis, we consider the modelingof dynamic spectrum sharing in the market with multiple strategic PUs and SUs. In thisnew model, we assume that SUs use the same power to transmit their own signal andrelay the signal of primary PUs, Besides, the SUs could adapt their transmitting poweraccording to the spectrum competition results. Later, we study the spectrum leasingproblem from optimizing the utility of secondary network, the utility of primary network and the entire network(including primary network and secondarynetwork)respectively. Finally, we give the simulation results and analyze the simulationresults.On the other hand, most of the existing spectrum leasing algorithms assume thatone primary user can only lease its spectrum bandwidth to only one secondary user,Besides, these work use either underlay spectrum sharing model or overlay spectrumsharing model. Thus, We combine the underlay and overlay dynamic spectrum sharingmechanisms in the our new model, which allows one primary user to lease its spectrumto multiple secondary user, Later we analyze the model with evolutionary game theoryand propose the corresponding iterative algorithm to achieve ESS. Finally, we give thesimulation results and analyze the corresponding relationship between simulation resultsand theoretical algorithm.