Coupling Strategy Game Based On The Spectrum Allocation Algorithm

With the rapid growth of mobile radio systems, there is growing demand for spectrum, which in practice means that there is a need for more efficient use of spectrum which could lead to improvements in useful communication capacity. Advancements in technology are enabling the development of radio systems that have the potential to use the spectrum much more dynamically and efficiently. Among such advancements, cognitive radio systems not only have the potential to make more efficient use of spectrum, but to also offer more versatility and flexibility. Our studies mainly focus on dynamic spectrum allocation algorithm in cognitive radio system. According to the game theories, this dissertation mainly analyzes the spectrum sharing and allocation problems through optimal method and hierarchical decomposition in cognitive radios.Firstly, this article introduces the basic concept of cognitive radio, the main function, the rule and approach of spectrum allocation. And we introduce the elements of game theory and the basic model, as the theoretical basis for this dissertation.Secondly, based on cognitive radio systems, it presents a cognitive model studied in this paper. In this model, the interference caused to the primary users due to the secondary users'transmissions is measured in real time by monitoring station and fed back to the cognitive user through the agreed channel. Then cognitive user adjust its power allocation to make the interference below the defined primary users'interference constraints. We also analyze single-user water-filling algorithm with interference constraint which pave the way for multi-user power allocation.Moreover, we analyze the power allocation among multi-users through game theory in cognitive radios and build a game theory model. Then we decompose the game model into two sub-problems through the optimization algorithm and the hierarchical decomposition theory. The original problem is transformed into a non-coupled model, and then a distributed spectrum allocation algorithm.Finally, we simulate the spectrum allocation raised above. We simplify the model proposed in this paper for the complexity of the simulation. The proposed algorithm has good convergence and meet the primary users'interference and target rate constraint which can be seen from the simulation results. And the algorithm finally converges to the Nash equilibrium point quickly through the iteration and gives the cognitive users'power allocation scheme.