Research On Collaborative Spectrum Sensing Based On Coalition Formation Game In Cognitive Radio Networks

With the rapid development of wireless communication, the demand for spectrum is highly increased. The current allocation principle of spectrum is static and fixed. However, the utilization rate of spectrum is low with this method and this drawback is becoming more and more obvious under the circumstance of the mobile services explosion. The emergence of cognitive radio technology can make up for this disadvantage due to the maximum increase of the spectrum utilization. The research of this technology is of great importance since the spectrum sensing technology is a vital premise of spectrum management and distribution in cognitive network.The shadowing and hidden node will inevitably reduce the spectrum sensing performance in independent spectrum sensing. A new method combining game theory and spectrum sensing is brought up in this thesis. Firstly, do research on the different spectrum sensing technologies from different aspects and do comparative analysis on the advantages and disadvantages of these different methods. Focus on the cooperative spectrum sensing, data fusion rule and the game theory including the coalition formation game.Secondly, based on the research of the existing multi-user cooperative spectrum sensing technologies and coalition formation game, a method which applies the coaliton game algorithm to the cognitive radio is brought up in the single authorized spectrum and coexistence of multiple user system models. It introduces the algorithm in coalition utility value, coalition formation comparison rules, switch rules and forming process. Compare the simulation performance between the traditional non-cooperative multi-user cooperative spectrum sensing algorithm and the method in this article. The result shows that method in this article has better performance.Last, Expand the cognitive model by extending the single authorized spectrum to multiple authorized spectrum. The cognition time is set to varible based on the consideration of energy loss and sensing accuracy. Redifine the coalition head selection algorithm. Compare the improvment through simulation with two methods, one use coalition game with fixed time and the other abandon the coalition game. The result shows that method in this article has better performance.