双层卫星网络星座设计及用户接入算法研究

发布时间：2018-03-21 18:43

本文选题：双层卫星网络　切入点：星座设计　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】：混合卫星网络是为了弥补单层卫星网络的缺点而产生的，它综合了各单层卫星网络的优点，形成优势互补，为用户提供更好的服务质量。混合卫星网络的形式有很多，其共同点是都包含有多颗卫星，多颗卫星对地面的覆盖使得卫星接入算法对混合卫星网络的性能起到关键性的作用。不同的卫星接入算法对卫星的服务质量的影响各不相同，因此如何设计更好的混合卫星网络和卫星接入算法是目前研究的重点。本文根据对混合卫星网络特点的分析，设计了5GEO+66LEO的双层卫星网络并提出了多QoS约束的卫星接入算法，具体内容如下：首先，本文对混合卫星网络的结构和卫星接入算法的研究现状进行分析，在此基础上比较了各种卫星网络的优缺点，总结了单层卫星网络的缺点，并探讨混合卫星网络的优点。同时对已有的混合卫星网络进行简单的介绍，对混合卫星网络的拓扑结构进行分析。接下来，结合仿真结果，本文深入地分析和研究了典型卫星接入算法的性能。其次，在分析了GEO、MEO、LEO和HEO卫星网络各自的特点之后，综合其性能的好坏和设计实现的难易程度，本文设计并提出了5GEO+66LEO的双层卫星网络，该双层卫星网络中GEO和LEO卫星网络互相弥补了对方的不足之处，再加上GEO卫星技术成熟，LEO卫星实现容易，使得该双层卫星网络具有很高的可实现性。同时，使用STK搭建了该双层卫星网络模型，并对其可见性、覆盖特性和星间链路特性进行分析。最后，本文深入地分析和比较了典型的卫星接入算法，并在此基础上提出了多QoS约束的卫星选择算法。典型的卫星接入算法是从卫星的角度出发，通过分析卫星对用户的覆盖时间、用户到卫星的距离和卫星网络负载三个方面性能的好坏，选择合适的卫星进行接入。而本文提出的算法主要考虑用户的要求和卫星所提供的服务之间的差异度，选择差异度最小的卫星进行接入。接下来通过仿真分析，验证了该算法的正确性，同时将该算法和典型的卫星接入算法进行比较，证明了本文算法可以降低呼叫阻塞率、切换失败概率和强制中断概率，同时使网络平均负载维持较高的水平，，实现网络接入性能的提高。
[Abstract]:Hybrid satellite network is produced to compensate for the shortcomings of single-layer satellite network. It combines the advantages of each single-layer satellite network, forms a complementary advantage, and provides users with better quality of service. There are many forms of hybrid satellite network. The common point is that there are many satellites, and the ground coverage of multiple satellites makes satellite access algorithms play a key role in the performance of hybrid satellite networks. Different satellite access algorithms have different effects on the quality of service of satellites. Therefore, how to design better hybrid satellite network and satellite access algorithm is the focus of current research. Based on the analysis of the characteristics of hybrid satellite network, the double-layer satellite network of 5GEO 66LEO is designed and a multi-#en0# constrained satellite access algorithm is proposed. The details are as follows:. Firstly, the structure of hybrid satellite network and the research status of satellite access algorithm are analyzed in this paper. On this basis, the advantages and disadvantages of various satellite networks are compared, and the shortcomings of single-layer satellite network are summarized. The advantages of hybrid satellite network are also discussed. At the same time, the existing hybrid satellite network is briefly introduced, and the topology of hybrid satellite network is analyzed. The performance of typical satellite access algorithms is analyzed and studied in this paper. Secondly, after analyzing the characteristics of GEOOOOLEO and HEO satellite networks, and synthesizing their performance and the degree of difficulty in design and implementation, this paper designs and proposes a double-layer satellite network based on 5GEO 66LEO. In this double-layer satellite network, GEO and LEO satellite network make up for each other's shortcomings, and the GEO satellite technology is mature and easy to realize, which makes the double-layer satellite network highly realizable. The two-layer satellite network model is built with STK, and its visibility, coverage and intersatellite link characteristics are analyzed. Finally, this paper deeply analyzes and compares the typical satellite access algorithms, and puts forward a satellite selection algorithm with multiple QoS constraints. By analyzing the coverage time of the satellite to the user, the distance from the user to the satellite and the load of the satellite network, The algorithm proposed in this paper mainly considers the difference between the user's requirements and the service provided by the satellite, and selects the satellite with the least difference to access. The correctness of the algorithm is verified and compared with the typical satellite access algorithm. It is proved that the proposed algorithm can reduce call blocking probability, handoff failure probability and forced interrupt probability. At the same time, the average load of the network is maintained at a high level, and the network access performance is 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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