| With the development of power line communication technology, power line as a kind of the most widespread communication medium, has a unique advantage and incalculable market potential in many fields of high-speed data transmission, such as home automation,remote stopwatch, load control, broadband internet access and audio signal. OFDMA which is a new generation of broadband wireless access technology, with its high transmission rate,flexible resource allocation, and can support multiple users at the same time has been successfully applied in power line communication system. Resource allocation algorithm based on OFDMA appeared in succession, but its application in the power line communication system research is still in the initial stage. There are some shortcomings such as a large amount of calculation and not easy to achieve. So, this paper focus on power line communication system based on OFDMA technology resource allocation problems .In order to improve the resource utilization of power line communication system and service quality, on the basis of the research of the channel model of low voltage power line communication system , and the combination with OFDMA technology theory knowledge,this topic proposed a new resource allocation algorithm based on modified differential evolution algorithm. This algorithm takes rate adaptation as the criterion. Under the condition of the power spectrum limitation, the algorithm will dynamically allot subcarriers according to the user channel information to maximize the system throughput under the premise of different QoS requirements. The simulation experiment was taken in the environment of a typical power line communication system, and the result showed that the proposed algorithm has great improvement in user fairness and system capacity, and effectively improve the performance of power line communication system.In order to improve the resource utilization of power line communication system and service quality, on the basis of the research of the channel model of low voltage power line communication system , and the combination with OFDMA technology theory knowledge,this topic proposed a new resource allocation algorithm based on modified differential evolution algorithm. This algorithm takes rate adaptation as the criterion. Under the condition of the power spectrum limitation, the algorithm will dynamically allot subcarriers according to the user channel information to maximize the system throughput under the premise of different QoS requirements. The simulation experiment was taken in the environment of a typical power line communication system, and the result showed that the proposed algorithm has great improvement in user fairness and system capacity, and effectively improve the performance of power line communication system.Due to the different levels of resource allocation in power line communication system with different constraint conditions and optimization goals, we carried on the thorough research to the physical layer, link layer, network layer and application layer. Then, we proposed a cross layer resource allocation algorithm for mixed service, namely user scheduling algorithm based on utility function in the data link control layer and the subcarrier and power joint allocation scheme based on the priority in the physical layer. In the data link control layer,the user’s priority will be determined through the comprehensive consideration of channel state information, business model, the queue status information and QoS requirements; in the physical layer, combined with rate adaptation and margin adaptation criteria, it will dynamically allot subcarriers and power resources according to the users’priority for each user. The idea is to minimize the waste of resources caused by blind distribution, with as little resources as possible to meet the minimum rate requirements. Under the premise of guarantee the user fairness,if the remaining resources can meet the users’maximum permission rate, the maximization of remaining resources will be the optimization goal, otherwise, the maximization of system throughput will be the optimization goal. The experimental results show that, compared with existing algorithms, this topic proposed algorithm can satisfy the user fairness and service quality, and be able to use fewer resources to get a bigger system throughput. |
