Research And Simulated Implementation Of Network Resource Allocation Method For LEO Satellite Constellation System

Since the satellite communication network has the characteristics such as global communication, fast information transmission, wide coverage and without geographical constraints, and it has been widely used in military affairs and civilian engineering. It has great guiding significance for design a cost-effective satellite communication network to study the satellite resource allocation in different scenarios and maximize the network carrying capacity.This thesis uses network capacity to measure network carrying capacity. With the help of the proposed network capacity analysis method, satellite bandwidth and power resources allocation methods under different demand are studied with taking LEO satellite communication environment. Firstly, LEO satellite node model, inter satellite link model and transmission model are established. Secondly, the network capacity is divided into the instantaneous network capacity and the average network capacity. According the inter-satellite link switching time divide the cycle into several time slice, a large number of sampling points in each time slice is selected to calculate the average network capacity of a time slice and then calculate the overall network capacity. Finally, some resource allocation method are designed from different perspective of demand, including a maximum capacity based resource allocation method, an utility function based resource allocation method and a proportional fairness based resource allocation method. The maximum capacity based resource allocation method aims at maximum capacity without considering fairness between adjacent satellite and the actual demand, which is an ideal way. The utility function based resource allocation method maximizes the satisfaction of adjacent satellites to allocate resource. The proportional fairness based resource allocation method takes into account the number of ground stations within the satellite coverage areas and lifespan of the corresponding satellite-ground station link. These resource allocation methods are regarded as nonlinear mixed-integer optimization problems. So a multi population cloud differential evolution algorithm with integer operations and a swallow swarm algorithm are employed to solve them respectively.In order to verify the effectiveness and feasibility of designed resource allocation methods, Iridium system’s and Globalstar system’s satellite orbital data are produced by STK (Satellite Tool Kit) and the simulation program is developed with Eclipse platform. The results show that the network capacities under different resource allocation methods are different, and the overall carrying capacity of the satellite communication network is affected by the satellite trajectory and the actual business.