Research On Resource Management Of Cross-layer Design Technology Over Satellite System

Currently, with the development of wireless communication technology, thedevelopment trend of future wireless communication is to communication forheaven and earth. Satellite network has the characteristics of widely covering anddistance insensitive, and it can make up the cover lank of cellular network.Nowadays, satellite communication has become an important part of the network. Itcan bear all kinds of media business, which has mode demand for the resource.Therefore, it is one of the most important problems to be solved in satellitecommunication.This paper is focusing on optimizing the resource management problem insatellite communication system. We adopt the DVB-RCS (Digital VideoBroadcasting-Return Channel Satellite) deal in satellite communication system.This paper researched mainly on physical layer, MAC layer and application layerdesign as well as bandwidth allocation and packet scheduling. First, we analyzedthe cross-layer technique and traditional OSI (Open System Interconnection, OSI)deal in wireless communication system. Since cross-layer technique applied onsatellite communication system is still at the researching beginning, this paperresearches on bandwidth allocation optimization in forward link and packetscheduling in the downlink.According to the contradict of limited resource and user demand in satellitecommunication system, this paper proposed a cross-layer model based on networkutility maximization. Through utilizing the network utility to combine theparameters in different layers together, we can optimize the bandwidth allocationproblem. Use the model of network utility maximization and consider both theutility effect as well as fair effect, we can allocate the limited resource to multipleusers.After using this optimization algorithm solving the cross-layer optimizationproblem, we also compare the result with the typical algorithm with OSI deal. It canbe seen through the result that the proposed method can achieve a betterperformance for both throughput and fairness. Besides, we also researched on thepacket scheduler to achieve a better scheduling in the downlink of satellitecommunication system with DVB-RCS deal. Through considering all the factors,such as the adaptive coding and modulation in physical layer, the queuing model inMAC layer and QoS demand in the application layer, the cross-layer packetscheduler is designed and optimized. The first algorithm is typical robin to queue the packet according to the users. The second algorithm is adaptive weights robin,through which all the packets can be queued according to the channel information atphysical layer. After all the whole design, the simulation results show that theperformance of both bit error rates and throughput are optimized compared to thetypical round robin scheduler.