本文選題：衛(wèi)星多媒體網絡　切入點：跨層設計　出處：《哈爾濱工業(yè)大學》2014年碩士論文　論文類型：學位論文

【摘要】：隨著無線通信技術的不斷發(fā)展，空天地一體化已經成為了未來無線通信領域的發(fā)展趨勢。衛(wèi)星網絡由于其具有覆蓋范圍廣和對距離不敏感等特點，可以很好地填補了地面蜂窩網絡覆蓋范圍的空白，已經成為了空天地一體化信息融合網絡體系的重要組成部分。衛(wèi)星網絡現在可以承載各種各樣的多媒體業(yè)務，，而多媒體業(yè)務的傳輸對于衛(wèi)星系統(tǒng)所能夠提供的帶寬資源提出了更高的要求。因此，如何在衛(wèi)星通信系統(tǒng)中對無線網絡資源進行管理，保障用戶終端的業(yè)務服務質量需求是當前面臨的問題之一。在衛(wèi)星這種網絡環(huán)境處于動態(tài)變化的通信系統(tǒng)中，傳統(tǒng)的分層協(xié)議設計方式很難實現數據傳輸的最優(yōu)化設計。為了解決衛(wèi)星網絡資源的優(yōu)化設計問題，人們提出將跨層設計的思想應用在衛(wèi)星通信系統(tǒng)中，打破傳統(tǒng)協(xié)議層固定的傳輸模式，通過層與層之間信息的綜合利用，實現系統(tǒng)資源利用率的提高。 本文主要研究了DVB-RCS(Digital Video Broadcasting-Return ChannelSatellite)協(xié)議下的衛(wèi)星通信跨層系統(tǒng)的資源管理問題。詳細論述了跨層技術的實現原理，對于OSI(Open System Interconnection, OSI)七層協(xié)議中的各個協(xié)議層功能進行了分析，研究的重點是該傳輸系統(tǒng)的上行鏈路帶寬分配和下行鏈路數據包調度問題。首先，針對衛(wèi)星通信系統(tǒng)的資源有限性和用戶需求之間的矛盾，提出了一種基于效用函數最大化的跨層帶寬分配優(yōu)化模型，設計了一種可以將不同層間參數聯合的跨層效用函數，即將應用層的服務質量要求，物理層和信道狀態(tài)相關的自適應調制編碼方式，數據鏈路層排隊的優(yōu)先級等參數結合。在求解該基于效用函數最大化的數學模型的過程中，兼顧考慮系統(tǒng)的效用以及公平性，提出了一種優(yōu)化迭代算法，將有限的帶寬資源優(yōu)化分配給多個用戶。對這種效用函數最大化跨層優(yōu)化帶寬分配算法的系統(tǒng)性能進行了仿真分析，本文提出的效用函數以及相應的優(yōu)化算法在公平性和吞吐量上都優(yōu)于一般化的效用函數最大化方法和經典的注水迭代算法。其次，本文對于該系統(tǒng)的下行鏈路的數據包調度器進行了優(yōu)化，提出了一種考慮了物理層自適應調制編碼技術，數據鏈路層排隊方法以及應用層服務質量結合的跨層調度策略。該系統(tǒng)中地面控制中心的調度結構主要包括優(yōu)化調度模塊和自適應模塊，調度模塊結合了輪詢調度算法和自適應加權調度算法，經過跨層優(yōu)化后的系統(tǒng)仿真結果表明，誤碼率性能明顯優(yōu)于僅采用輪詢調度方法的調度器，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.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN927.2

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相關期刊論文 前1條

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