Coordinated Wireless Resource Optimization Allocation In Multi-cell Networks

With the rapid development of the cellular mobile communication system, the spectrum resources are increasingly short, but the requirements of data transmission by the users are increasingly high. How to optimize the existing spectrum resources and effectively utilize the limited spectrum resources available is a focus of the current research. OFDMA is one of the core technologies of the next-generation mobile communication system, and resource allocation significantly affects the performances of the OFDM system.The intra-cell interference has been well solved in the cellular mobile communication system based on OFDMA. However the inter-cell interference is the main problem affecting the performances of the system. Because the allocations for each cell will impact the other cells'functions, we need to study the dynamic resource allocation algorithm for multi-cell OFDMA system. In this algorithm, resources are allocated for users adaptively according to the users'channel instantaneous gain information, and the resource utilization rate and system capacities are effectively improved while satisfying certain constraints. In the multi-cell network, we study the dynamic resource allocation algorithm for the OFDMA system from rate adaptive rules in this paper.The main contents and innovative points in this paper mainly include the followings:1,Firstly, we form a power allocation model for the multi-cell OFDMA system and treat optimization of the network utility subjected to the power limitations of each base station as the optimal objective. In order to use the distributed method to solve the utility optimization problem for the network and to overcome the inefficacy of the pure non-cooperative game and the huge expenses of the cooperative game, we put forward a Non-Cooperative Power allocation Game via Pricing mechanism algorithm (NCPGP). By exchanging the channel information to adjust the transmission powers of the adjacent cells, the inter-cell interference can be restrained and the system utility can be enhanced. In this paper, we design an efficient distributed price mechanism, also we theoretically prove the existence of the Nash equilibrium and the convergence of the NCPGP. The simulation results show that the functions of the network using the NCPGP are obviously boosted, compared with the network using NCPG algorithm, water-filling algorithm and the average power allocation algorithm respectively. Especially when the interference of the sub-carriers on the common channel between cells is quite serious, the game via pricing mechanism has superior performances.2,Because of the existing frequency selectivity on wireless channels, so not all the sub-carriers are in deep fading. In the multi-user system, for one user, the sub-carrier may be not appropriate for him. But for another, it may be a better one. Therefore, the sub-carrier with the high SINR can be fully used by the dynamic sub-channel allocation and then the performances of the system are accordingly enhanced. On the basis of the NCPGP algorithm, we present the resource allocations algorithm for the multi-cell OFDMA system via non-cooperative game. We firstly define the weighed data rates and the utility function of a single cell. Then the utility maximization problem is transformed into a non-cooperative resource allocation game constrained by the maximum power. In this game, the base stations in each cell realize their own utility maximization by controlling sub-carriers and power allocation, respectively. The simulation results illustrate that the proposed algorithm, relative to pure non-cooperative resource game theory, can make the system resource capacity significantly increase, and the system functions which are implemented by the sub-carrier dynamic allocation are better than the sub-carrier static allocation.3,Considering the power of the base station in the real scene can not be continuously adjustable, we study the jointly optimal discrete power control and sub-carriers scheduling problem. Based on game theory, we use the distributed method to solve the network utility maximization problem. For avoiding the Nash Equilibrium points obtained from the best response/better response convergence methods are not ideal optimal solutions and also avoiding the huge network expenditure generated by exhaustive method, we propose the utility maximization algorithm based on consultation mechanism. Through adaptive allocating the sub-carriers and power levels, the system utility maximization are realized subjected to the maximum powers of each base station. Also we theoretically prove the algorithm with very high probability converges to the globally optimal. This property can be observed in the simulation process.