Research On Spectrum Allocation In Cognitive Radio Networks

With the wide application of emerging wireless communication technology,demand for the radio spectrum is getting greater and the conflicts between limitedresources and ever-increasing demand are getting much more obvious. As a kind ofintelligent spectrum sharing technology, the environmental, behavioral and targetconsciousness of cognitive radio enable the cognitive radio share resources withprimary users in the frequency domain, time domain and airspace domain to improvethe utilization rate of spectrum, easing the conflicts mention above. Game theory is kindof basic theory, using mathematical model to make decision and to optimize ofdecision-making. For competing limited network resources, cognitive users canconstruct game model to design more efficient and reliable resources allocationstrategies. This dissertaiont focuses on the study of spectrum allocation in cognitiveradio system, and the main research work are as follows:①Game theory is used to analyze the problem of cognitive radio spectrumallocation and construct spectrum allocation algorithm base on Cournot game modeland Bertrand game model respectively. The two algorithm utilize the utility functionwhich takes substitution factor into consideration to solve the quantity and the priceproblem respectively on spectrum allocation. And detailed analysis of influences thatthe number of primary users, channel quality, learning rate and substitution factor exerton the performance of these two game model is offered.②Based on the in-depth study of price-based spectrum allocation algorithm, animproved spectrum allocation model considering user’s mobility was proposed. In thismodel, QoS was presented by SNR and the algorithm derives the total amount ofspectrum demand by the constrain relationship between the price and demend of thespectrum. Simulation results illustrate that the price of the spectrum, bandwidthrequirement and user profits vary with user movement. And there is a best positionmaximize user profits in the process of user movement.