| The technological trend of the next generation of mobile communication system centers on high speed, high capacity, low cost, multi-service, adaptiveness and extensibility. And for the development of it, the problems of improving spectrum efficiency, increasing the system capacity of the valid users and adapting to the high-speed data transmission in wireless environment must be solved. MIMO-OFDM, as a kind of technology with great development potential, receives widespread concern now. With the combination of MIMO technology and OFDM technology, MIMO-OFDM solves the above-mentioned problems and has achieved a great improvement in system capacity and spectrum efficiency. However, it also brings many new problems to the wireless resource allocation. Therefore, this paper mainly studies the resource allocation algorithm in wireless communication networks with the theoretical basis of MIMO-OFDM system.1. Based on the wireless communication network structure of the next generation and the different types of the communication business, this paper analyzes the status quo of the research on the resource allocation algorithm in wireless communication networks including the physical resource allocation algorithm in MIMO-OFDM system, media access control layer resource allocation algorithm in MIMO-OFDM system and cross layer resource allocation algorithm in MIMO-OFDM system.2. This paper introduces some basic relevant knowledge about MIMO technology and OFDM technology of mobile communication system, and makes a detailed introduction of the characteristics and advantages of them. According to their technical characteristics, this paper further studies and analyzes the MIMO-OFDM system model.3. The base station needs to know the terminal channel information on each sub-carrier when it allocated resources. And the downlink link channel information must though a specific feedback channel and feedback to the base station after user's estimate. The feedback information of the multi-user MIMO-OFDM systems is very big when there is large number of users, the sub-carriers and antennas. So it needs to reduce the feedback quantity of channel information in the condition of guarantee system performance. This paper analyzed the information feedback mode of MIMO-OFDM system and the channel's frequency domain correlation which is the base root of limited feedback algorithm. Then it simply introduced the inevitable quantitative problem in digital system feedback. After analyzing related bandwidth,the limited channel quantization and parameter selection of feedback, this paper puts forward a limited feedback algorithm based on cluster threshold. Simulation results show that the algorithm greatly reduces the feedback quantity of channel information in the condition of guarantee system performance.4. The traditional resource allocation algorithms don't take into account the upper link queuing, delay and other information. It can't have a good coordination of business resource allocation among users, so it causes a system waste of resource. According to business types, this paper proposes a kind of MIMO-OFDM system cross layer resource allocation algorithm. In the actual operation, there are four modules in our design, these are business classifier,access control modules,scheduler and resource allocation modules. Then it uses access control modules to process the business access request and schedule in terms of the QoS parameters of business access requirements and CSI of user's feedback. At last, it allocates the channel,bits and power to users according to priority scaling factor in the physical. Simulation results show that the algorithm meets the proportion fairness of users, and meanwhile, improves the spectrum efficiency greatly. |
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