Research On Spectrum Shairng Algorithm For Cognitive Radio Network Based On Game Theory

In recent years, with the rapid development of the wireless communication and business in theseamless, intelligent, broadband direction, spectrum resource which people demand is more andmore big, we have to face the problem of the lack of spectrum resource. At present, fixed allocationfor spectrum resource often bring up uneven distribution, and even a waste of the resource. Thesituation conflicts with the current shortage of spectrum resource. The limited available spectrumand low frequency spectrum utilization determines the need for a new means of communication.Cognitive radio as a new spectrum sharing technology can effectively alleviate the above problem,sensing frequency domain, learning the external environment, and changing system parameters inreal-time, it can automatically reuse the non-renewable resource. Spectrum sharing technology isone of the key technology of cognitive radio, which is to solve the problem of spectrum using whenmonitoring the idle spectrum.According to the shortage that the existing spectrum sharing algorithms have been influenced bysignal-to-noise ratio and interference gain, this thesis propose a power control algorithm based ongame theory, take full advantage of the interactive water-filling method and frequency divisionmultiplexing method, achieve lower cognitive inter-cell co-channel interference and improvespectrum utilization. The algorithm is based on a simplified two-user game model, under thedifferent game scenes in interference-limited cognitive wireless environment, according to thechannel’s interference gain and signal-to-noise ratio, proposed in low signal-to-noise ratio and weakinterference gain using iterative water-filling method, when high signal-to-noise and interferencegain using the frequency division multiplexing method. The simulation results show that the methodis effective to improve the spectrum utilization.Due to the benefits of single game is not a global optimal solution, in order to help the cognitiveradio user out of the prisoner’s dilemma, maximize spectrum utilization, this thesis proposed aspectrum sharing algorithm based on repeated games, using the trigger strategy of game theory toget the Pareto optimal solution, and analyze the influence of the discount factor, transmit power,noise power, as well as the convergence index on the algorithm. Finally, in random channel, itverified that this method is superior to other multiple game algorithms on anti-interference, andsolve the problem of the maximization of spectrum utilization.