Radio Resource Management Algorithm Research For Multiple Antennas System

Multiple antennas technique is one of the key techniques for 3G and the future generation mobile communications. Multiple antennas system is a kind of techinque with combining spatial field with time field of signal. Multiple-Input Multiple-Output technique can exploit spatial resource fully and improve system capacity and reliability without increasing spectrum resourece and transmission power. It can extend spectrum utilization ratio and increase transmission speed in theory. At one time it also can enhance anti-interference and anti-fading performance of communication system. The target of radio resource management is to guarantee quality of service of with limited resource and to improve network ulitization ratio (increase system capacity; decrease energy/power cost; keep small signaling load; lower cost). At one time it can prevent from blocking network. Considering the character of multiple antennas and the targets of radio resource management if both of them can be combined to think, their advantages can be exploited fully. Thus radio resource can be saved and the performance of system can be improved. So this thesis mainly focus on the research of radio resource management in multiple antennas system. The main contents and contributions of this thesis are as follows:1. The characters of conventional weighted fair queuing are systematically studied. A novel spatial multiplexing multiuser access scheduling algorithm based on weight fair queuing is proposed to solve the problem, which is that conventional weighted fair queuing doesn't improve system capacity. This proposed algorithm combines the fair scheduling strategy at the upper layer with the optimal antenna assignment at the physical layer. Branch and bound technique is used to search the optimal results. Simulation results show that the proposed algorithm has better performance than WFQ.2. The common techniques of radio resource management and the concept and the performance parameter of QoS are systematically summarized. The problem that is that the transmission delay of data will be different according to different length of packet data and different channel condition of each user will be ignored easily in multi-users entironment so adaptive delay fairness scheduling algorithm is propoesd. In each scheduling time slot, the users who have minimum delay are selected according to channel conditions and the length of packet data of users while average transmission delay of each user is updated. In terms of updated average transmission delay the users are selected adaptively so that the users with different channel conditions and the length of packet data can obtain fair scheduling chance. Simulation results show the proposed algorithm has better performance than classic RR and Max SNR.3. The history and concept of cognitive radio and the model of game theory are introduced. The feasibility of using game theory to cognitive radio is analyzed. According to the autonomous character of cognitive radio their interaction can be modeled as a game theoretic framework. Global mutual information is constructed as utility function and genetic algorithm is adopted to obtain Nash Equilibrium, which ensures the global optimum of the iterative results.4. BLAST technique is systematically researched. The theory and signal construction method of BLAST system are introduced. The main several signal detection algorithms also are introduced. Then the influence of interferences of other cells on the performance of BLAST system is analysed. Aimed at this problem, the interference mitigation based on game theory is proposed. This algorithm applies game theory to interference mitigation of multi-cell in BLAST system. Interference of multi-cell in BLAST system is made as game theory model. Finally the best response criterion is used to obtain Nash equilibrium.5. The theory of array antenna is systematically summarized. The conventional rules for adaptive beamforming are introduced. We analyze that the mutual interference between users is formed in the multi-users environment and the global performance is influenced. The adaptive beamforming algorithm based on game theory is proposed. Transmission weights adjustment of different users are described as a multi-users game. The existence and uniqueness of the Nash equilibrium in the adaptive beamforming algorithm based on game theory are proved by mathematics derivation. Convergent transmission weights update algorithm is designed. The performance of the propoesd algorithm is proved by simulation.