本文關(guān)鍵詞：基于多代理的認知衛(wèi)星通信架構(gòu)及頻譜感知算法的研究　出處：《北京交通大學》2017年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 認知衛(wèi)星通信網(wǎng)絡 頻譜感知代理 干擾概率 平均吞吐量

【摘要】：無線電是衛(wèi)星通信網(wǎng)絡的主要通信手段之一,目前主要采用時分復用技術(shù),但是該技術(shù)未能有效地利用現(xiàn)有頻譜資源,通信容量的擴充也只是依靠高頻帶寬來完成。因此,如何在衛(wèi)星通信中充分利用有限的頻譜資源提高網(wǎng)絡吞吐量,避免出現(xiàn)頻譜資源的"假性枯竭"問題,是目前研究的熱點問題之一。本文首先對衛(wèi)星通信網(wǎng)絡以及認知無線電(Cognitive Radio,CR)基礎(chǔ)知識進行了介紹,從理論的角度分析CR技術(shù)在衛(wèi)星通信網(wǎng)絡的可行性和先進性。在此基礎(chǔ)上,重點研究了基于多代理的認知衛(wèi)星通信架構(gòu)以及基于干擾的頻譜感知算法。論文主要工作如下:(1)提出了基于多頻譜感知代理(Spectrum-sensing Agent,SA)的認知衛(wèi)星通信架構(gòu)。首先,分析了認知衛(wèi)星動態(tài)接入空閑授權(quán)頻段的可行模式。針對傳統(tǒng)CR網(wǎng)絡在衛(wèi)星通信中面臨的挑戰(zhàn),提出由SA代替認知用戶執(zhí)行頻譜感知,并建立了基于多SAs的認知衛(wèi)星通信架構(gòu)。然后具體介紹了該架構(gòu)的網(wǎng)絡框架、功能框架以及頻譜感知運行模式和幀結(jié)構(gòu)。最后提出以通信吞吐量作為性能指標。該架構(gòu)不僅降低了認知用戶硬件設(shè)計的復雜度、成本以及額外的能耗,還增加了認知用戶的通信時間,進而提高了認知網(wǎng)絡的通信吞吐量。(2)提出了基于干擾的多代理頻譜感知算法,并得到不同情況下認知用戶以及網(wǎng)絡的平均可實現(xiàn)吞吐量。該算法根據(jù)垂直模式下認知衛(wèi)星利用地面授權(quán)頻段做上行通信的情況,建立詳細的網(wǎng)絡模型和多代理頻譜感知模型。利用主用戶接收機的信噪比門限定義干擾概率,根據(jù)距離分布函數(shù)得到整個網(wǎng)絡的干擾概率期望。通過干擾建模,分析認知用戶和主用戶共享相同頻段的可能性,最后得到不同情況下認知用戶以及網(wǎng)絡的平均可實現(xiàn)吞吐量。(3)仿真對比實驗驗證了基于干擾的多代理頻譜感知算法的性能。針對認知衛(wèi)星利用地面授權(quán)頻段做上行通信的情況,使用不同融合規(guī)則和主用戶信噪比門限,從吞吐量方面將基于干擾的多代理頻譜感知算法與傳統(tǒng)CR算法進行比較。結(jié)果表明,該算法的平均吞吐量不再隨著感知時間的增加而減少,并且相較于傳統(tǒng)CR算法,提高了認知用戶以及網(wǎng)絡平均可實現(xiàn)吞吐量,有利于進一步實現(xiàn)頻譜資源利用率的提高。本文最后進行了總結(jié),并對認知衛(wèi)星通信后續(xù)在寬帶頻譜感知技術(shù)、融合決策算法以及數(shù)據(jù)庫資源動態(tài)管理和更新等方面的研究進行了展望。
[Abstract]:Radio is one of the main means of communication in satellite communication networks. At present, time division multiplexing (TDM) technology is mainly used, but this technology can not make effective use of the existing spectrum resources. The expansion of communication capacity only depends on high frequency bandwidth. Therefore, how to make full use of limited spectrum resources to improve network throughput in satellite communications, and avoid the problem of "pseudo exhaustion" of spectrum resources. This paper first introduces the basic knowledge of satellite communication network and Cognitive Radio CRs. The feasibility and advancement of CR technology in satellite communication network are analyzed theoretically. The architecture of cognitive satellite communication based on multi-agent and spectrum sensing algorithm based on interference are studied in detail. Spectrum-sensing Agent. Firstly, the feasible mode of cognitive satellite dynamic access to idle authorization band is analyzed. Aiming at the challenges of traditional CR network in satellite communication. A new cognitive satellite communication architecture based on multiple SAs is proposed, which is implemented by SA instead of cognitive users. Then, the network framework of this architecture is introduced in detail. Finally, the communication throughput is proposed as the performance index. This architecture not only reduces the complexity, cost and additional energy consumption of the hardware design of cognitive users. In addition, the communication time of cognitive users is increased, and the communication throughput of cognitive networks is improved. (2) A multi-agent spectrum sensing algorithm based on interference is proposed. The average throughput of cognitive users and networks under different conditions is obtained. The algorithm makes uplink communication according to the vertical mode of cognitive satellites using terrestrial authorized frequency bands. A detailed network model and a multi-agent spectrum sensing model are established. The interference probability is defined by the signal-to-noise ratio threshold of the primary user receiver, and the interference probability expectation of the whole network is obtained according to the distance distribution function. Analyze the possibility of cognitive users and primary users sharing the same frequency band. Finally, the average realizable throughput of cognitive users and networks under different conditions is obtained. The simulation results verify the performance of the multi-agent spectrum sensing algorithm based on interference, aiming at the uplink communication of cognitive satellite using the ground authorized frequency band. Using different fusion rules and signal-to-noise ratio (SNR) threshold of the primary user, the interference based multi-agent spectrum sensing algorithm is compared with the traditional CR algorithm in terms of throughput. The average throughput of the algorithm is no longer reduced with the increase of perceptual time, and compared with the traditional CR algorithm, the average throughput of cognitive users and network can be improved. It is helpful to further improve the efficiency of spectrum resources. Finally, this paper summarizes the cognitive satellite communication follow-up in broadband spectrum sensing technology. The research of fusion decision algorithm and database resource dynamic management and update are prospected.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN925;TN927.2

【參考文獻】

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1 張乃通;趙康P，

本文編號：1421216