Adaptive Wireless Resource Allocation For OFDMA System Based On Game Theory

OFDMA has become the key transmission technologies for 4G mobile communication systems. Combining with adaptive technologies, frequency diversity and multiuser diversity can be effectively utilized to enhance the spectral efficiency of wireless communication systems. Game theory is a good mathematical tool for researching the competing behaviors and it has been widely used in wireless communication systems. Game theory can provide innovative research thought and algorithms to enhance the performance of wirless communication systems. Based on game theory, the main contribution of this doctoral dissertation is to provide significative research results for resource allocation field, including innovative concepts, universal analytical thought and resource allocation algorithms.In the field of proportional fairness, we introduce auction theory to research it for the first time. Based on optimization theory, the proportional fair objective function is investigated in detail, and the connotive economic meaning of the resource allocation process is also shown. Prirotiy-ranked bargaining framework is then proposed from auction theory. Simulation results show that the proposed scheme can realize proportional fairness criterion for uplink OFDMA system. When the proportional fairness index is set to proper value, the proposed scheme can realize the results of Nash fairness and max-min fairness, which embodies the universial meaning of the research work.Considering the fact that previous work in dynamic resource allocation field mainly focus on designing algorithms for a certain objective function, we target to propose a unified resource allocation framework in this dissertation. The mathematical tools include optimization theory, non-cooperative game theory and matrix theory. The most differences between previous works are:the concept of player is revised; several innovative concepts, theories and bargaining principle are proposed. Then the unified resource allocation scheme-simultaneously bargaining algorithm is proposed. Simulation results show that simultaneously bargaining algorithm can outperform the most efficient suboptimal schemes in most cases, and it can also realize Nash fairness and max-min fairness. In addition, the divergency of previous algorithm for Nash fairness is also overcome. These facts denote the universial meaning of the proposed unified resource allocation scheme.In the case of partial channel side information, we investigate the optimal resource allocation scheme for the case of fast fading. According to outage theory, the fading channel is modeled as two time-scale channel. Optimization theory is utilized to analyze the objective function, and surplus function in the economic field is utilized to characterize the optimal solution. By revising the concept of surplus function, the analyses are extended to discrete block case and optimial resource allocation algorithm is obtained for non-accurate fading channel. Surplus function is the key technology of this chapter's research work and it can analyze more complex outage issues by combining with more game theoretical thoughts.In the field of multi-cell resource allocation, we dedicate to proposing distributed interference suppressing algorithm. Starting from single subcarrier case, the effect of inter-cell interference to the total capacity is discussed in detail, and then the analytical result is extended to multi-carrier case. The proposed distributed scheme allows each cell to allocate the resources independently, and the base station controller is responsible for gathering the allocation information. By checking out each subcarrier, the base station controller would evaluate each base station's sharing behavior, and adjust the Nash equilibrium to enhance the performance. Simultion results show that the proposed scheme can greatly enhance conventional distributed scheme's spectral efficiency and normalized spectral efficiency, and save transmission power for wireless communication system.In the field of cognitive radio, we mainly investigate the distributed spectrum sharing technologies. By modeling each cognitive radio user as a pair of transmitter and receiver, we set interference temperature limit for protecting the primary system and research distributed spectrum sharing behaviors based on the kinds of exchange information. In order to utilize the classic game theory, we propose the concept of relaxed game to deal with the interference temperature limit. The convergence issue, uniqueness of Nash equilibrium and the equivalence to original game are discussed in great detail. Simulation results show that the proposed three schemes can effectively deal with co-channel interference limit issues, and allow the cognitive radio system to flexibly utilize the unlicensed spectrum and work harmoniously with the primary system.