本文選題：網(wǎng)絡調(diào)制技術　切入點：星座點映射　出處：《哈爾濱工業(yè)大學》2014年碩士論文

【摘要】：網(wǎng)絡調(diào)制技術是一種根據(jù)發(fā)送信息的相對重要性而建立的保護度機制,其系統(tǒng)模型為基于中繼的三點式網(wǎng)絡拓撲結構。在本篇論文中,首次將網(wǎng)絡調(diào)制技術應用于深空通信中,提出了深空通信中一種基于中繼的網(wǎng)絡調(diào)制拓撲結構,主要目的在于折中系統(tǒng)可靠性與有效性,即在保證一定系統(tǒng)可靠性的前提下,大幅度提升系統(tǒng)有效性。研究的主要內(nèi)容包括:網(wǎng)絡調(diào)制技術的星座映射規(guī)則、不同映射規(guī)則及不同解調(diào)方法所帶來系統(tǒng)性能影響、衡量系統(tǒng)可靠性及有效性的兩個重要指標:誤碼率以及吞吐量的計算原理及公式推導這三個方面。本文對網(wǎng)絡調(diào)制技術的系統(tǒng)模型、傳輸機理以及星座點映射規(guī)則做了詳細介紹。網(wǎng)絡調(diào)制技術的不同星座點映射規(guī)則及不同的解調(diào)方法對系統(tǒng)性能影響是不同的,本文以三跳鏈路中某一鏈路采用Gray映射的8PSK網(wǎng)絡調(diào)制技術為例,提出了整體解調(diào)法及逐位解調(diào)法,并對兩種不同的解調(diào)方法進行了Matlab仿真,通過對仿真結果進行分析,得出的結論是采用逐位解調(diào)法可以降低系統(tǒng)誤碼率。對系統(tǒng)誤碼率及吞吐量的計算公式進行了推導仿真。誤碼率及吞吐量是系統(tǒng)可靠性及有效性的主要表現(xiàn)形式,本文提出利用遞歸方法推導出在加性高斯白噪聲信道條件下通用分層PAM誤碼率公式,并對不同星座點映射規(guī)則的網(wǎng)絡調(diào)制技術進行了Matlab仿真及結果的分析比較。對于吞吐量的求解方法,利用網(wǎng)絡調(diào)制的傳輸模型,以香農(nóng)第二極限定理為依據(jù),推導出網(wǎng)絡調(diào)制系統(tǒng)吞吐量的求解公式,并應用Matlab仿真對采用不同調(diào)制類型的網(wǎng)絡調(diào)制的系統(tǒng)吞吐量進行了分析對比。通過仿真驗證了網(wǎng)絡調(diào)制技術應用于深空通信鏈路中可提升系統(tǒng)性能。以月地系通信鏈路為例,選取月地系拉格朗日L1點作為中繼衛(wèi)星的位置,通過Matlab仿真,把系統(tǒng)采用網(wǎng)絡調(diào)制技術、直傳鏈路調(diào)制以及單中繼兩跳鏈路調(diào)制這三種不同傳輸方式所得出的不同吞吐量曲線繪制在一幅圖中。通過對結果分析比較可得出結論:網(wǎng)絡調(diào)制技術應用于深空通信中可有效提升系統(tǒng)吞吐量,從而有效解決了深空通信中低有效性的難題。
[Abstract]:Network modulation is a protection mechanism based on the relative importance of sending information. Its system model is a three-point network topology based on relay. In this paper, the network modulation technology is applied to deep space communication for the first time. In this paper, a network modulation topology based on relay in deep space communication is proposed. The main purpose is to compromise the reliability and effectiveness of the system, that is, to ensure the reliability of a certain system. The main contents of the research include: constellation mapping rules of network modulation technology, different mapping rules and different demodulation methods bring about system performance impact. There are two important indexes to measure the reliability and effectiveness of the system: the calculation principle and formula derivation of error rate and throughput. The transmission mechanism and constellation point mapping rules are introduced in detail. Different constellation mapping rules and different demodulation methods of network modulation technology have different effects on system performance. In this paper, a 8PSK network modulation technique based on Gray mapping in a three-hop link is taken as an example. A global demodulation method and a bit-by-bit demodulation method are proposed. Two different demodulation methods are simulated by Matlab, and the simulation results are analyzed. The conclusion is that the bit by bit demodulation method can reduce the system bit error rate. The calculation formulas of the system bit error rate and throughput are deduced and simulated. The error rate and throughput are the main forms of system reliability and effectiveness. In this paper, a general hierarchical PAM BER formula for additive Gao Si white noise channel is derived by recursive method. The network modulation technology with different constellation mapping rules is simulated by Matlab and the results are analyzed and compared. The solution of throughput is based on Shannon's second limit theorem by using the transmission model of network modulation. The formula for solving the throughput of the network modulation system is derived. The throughput of network modulation with different modulation types is analyzed and compared by using Matlab simulation. It is verified by simulation that the application of network modulation technology in deep space communication link can improve the system performance. The position of lunar and terrestrial Lagrange L1 is chosen as relay satellite. The system is simulated by Matlab, and the network modulation technology is adopted. The different throughput curves obtained from three different transmission modes, direct link modulation and single relay two-hop link modulation, are drawn in a single diagram. By analyzing and comparing the results, it can be concluded that the network modulation technology is applied to the depth. In the air communication, the system throughput can be increased effectively, Thus effectively solve the problem of low effectiveness of deep space communication.
【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;TN911.3

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