卫星通信系统跨层资源管理技术研究

发布时间：2018-03-06 02:25

本文选题：卫星多媒体网络　切入点：跨层设计　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着无线通信技术的不断发展，空天地一体化已经成为了未来无线通信领域的发展趋势。卫星网络由于其具有覆盖范围广和对距离不敏感等特点，可以很好地填补了地面蜂窝网络覆盖范围的空白，已经成为了空天地一体化信息融合网络体系的重要组成部分。卫星网络现在可以承载各种各样的多媒体业务，，而多媒体业务的传输对于卫星系统所能够提供的带宽资源提出了更高的要求。因此，如何在卫星通信系统中对无线网络资源进行管理，保障用户终端的业务服务质量需求是当前面临的问题之一。在卫星这种网络环境处于动态变化的通信系统中，传统的分层协议设计方式很难实现数据传输的最优化设计。为了解决卫星网络资源的优化设计问题，人们提出将跨层设计的思想应用在卫星通信系统中，打破传统协议层固定的传输模式，通过层与层之间信息的综合利用，实现系统资源利用率的提高。本文主要研究了DVB-RCS(Digital Video Broadcasting-Return ChannelSatellite)协议下的卫星通信跨层系统的资源管理问题。详细论述了跨层技术的实现原理，对于OSI(Open System Interconnection, OSI)七层协议中的各个协议层功能进行了分析，研究的重点是该传输系统的上行链路带宽分配和下行链路数据包调度问题。首先，针对卫星通信系统的资源有限性和用户需求之间的矛盾，提出了一种基于效用函数最大化的跨层带宽分配优化模型，设计了一种可以将不同层间参数联合的跨层效用函数，即将应用层的服务质量要求，物理层和信道状态相关的自适应调制编码方式，数据链路层排队的优先级等参数结合。在求解该基于效用函数最大化的数学模型的过程中，兼顾考虑系统的效用以及公平性，提出了一种优化迭代算法，将有限的带宽资源优化分配给多个用户。对这种效用函数最大化跨层优化带宽分配算法的系统性能进行了仿真分析，本文提出的效用函数以及相应的优化算法在公平性和吞吐量上都优于一般化的效用函数最大化方法和经典的注水迭代算法。其次，本文对于该系统的下行链路的数据包调度器进行了优化，提出了一种考虑了物理层自适应调制编码技术，数据链路层排队方法以及应用层服务质量结合的跨层调度策略。该系统中地面控制中心的调度结构主要包括优化调度模块和自适应模块，调度模块结合了轮询调度算法和自适应加权调度算法，经过跨层优化后的系统仿真结果表明，误码率性能明显优于仅采用轮询调度方法的调度器，吞吐量也有所提高。
[Abstract]:With the continuous development of wireless communication technology, the integration of space, earth and earth has become the development trend of wireless communication field in the future. It can fill the gap in the coverage of terrestrial cellular network, and has become an important part of the integrated information fusion network system. Satellite network can now carry a variety of multimedia services. The transmission of multimedia services requires higher bandwidth resources provided by satellite systems. Therefore, how to manage wireless network resources in satellite communication systems, It is one of the problems to guarantee the service quality of service requirement of user terminal. In the communication system which is in the dynamic change of network environment such as satellite, In order to solve the problem of optimal design of satellite network resources, it is proposed to apply the idea of cross-layer design to satellite communication system. By breaking the fixed transmission mode of the traditional protocol layer and utilizing the information between the layers, the system resource utilization ratio can be improved. In this paper, the problem of resource management in cross-layer system of satellite communication under DVB-RCS(Digital Video Broadcasting-Return Channel Satellite is studied in detail. The implementation principle of cross-layer technology is discussed in detail, and the functions of each layer in OSI(Open System Interconnection (OSI) protocol are analyzed. The research focuses on the uplink bandwidth allocation and downlink packet scheduling of the transmission system. Firstly, the contradiction between the limited resources and the user requirements of the satellite communication system is discussed. A cross-layer bandwidth allocation optimization model based on maximizing utility function is proposed, and a cross-layer utility function is designed, which can combine the parameters of different layers, that is, the quality of service requirements of the application layer. The adaptive modulation coding method related to the physical layer and the channel state, the priority of the data link layer queueing and so on are combined. In solving the mathematical model based on the maximization of utility function, the utility and fairness of the system are taken into account. An optimal iterative algorithm is proposed to optimize the allocation of limited bandwidth resources to multiple users. The system performance of the utility function maximization cross-layer optimal bandwidth allocation algorithm is simulated and analyzed. The utility function proposed in this paper and the corresponding optimization algorithm are superior to the generalized utility function maximization method and the classical water injection iterative algorithm in fairness and throughput. In this paper, the downlink packet scheduler of the system is optimized, and a new adaptive modulation coding technique considering the physical layer is proposed. Data link layer queuing method and cross-layer scheduling strategy combined with application layer quality of service. The scheduling structure of ground control center in this system mainly includes optimal scheduling module and adaptive module. The scheduling module combines polling scheduling algorithm and adaptive weighted scheduling algorithm. The system simulation results show that the BER performance is obviously better than that of the scheduler only using polling scheduling method, and the throughput is also improved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927.2

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