Research On The Spectrum Sharing Algorithm For Cognitive Radios Based On Game Theory

With the rapid development and widespread application of wireless communication and multimedia technology, radio spectrum is becoming a scarce resource. However, many frequency bands are not used efficiently at most conditions. Cognitive radio is a novel approach for improving the utilization of radio spectrum. Cognitive radio is an intelligent wireless communication technique, can adapt its parameters according to the variations of environment, and opportunely switches to the bands which are not being used by the primary users, so it brings a promising future to solve the spectrum shortage, realize dynamic spectrum management and improve the efficiency of spectrum utilization.At present, researchers at home and abroad have proposed some system models and algorithms on spectrum allocation in cognitive radio. But these models and algorithms have their limitations. Models and algorithms based on other theoretical is still urgent for academia. It's a new way introducing game theory to cognitive radio technology research to solve the problem of cognitive radio spectrum allocation.In this thesis, a double-threshold detection method, which combines energy detection with cyclostationary feature detection, is put forward on the basis of the available spectrum detection method firstly. Secondly, the cognitive radio behavior is analyzed with game theory, and the system model of spectrum allocation is established. Thirdly, based on the system model, Cournot model algorithm and Stackelberg model algorithm, which are introduced from game theory, are designed to be used on spectrum allocation in cognitive radio. Finally, simulation is done for the situation that the total quantity and the price of the rental spectrum vary with the increasing of the quantity of the primary users. The simulation results show that the two algorithms increase the total quantity of the rental spectrum very much compared with the static spectrum allocation algorithm. The two algorithms can also reduce the price of the spectrum compared to the static spectrum allocation algorithm, which makes the second users want to rent more spectrums.