本文關(guān)鍵詞： MIMO 竊聽信道 空時分組碼 保密通信 保密容量　出處：《東華大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：無線通信的廣播特性使得無線網(wǎng)絡(luò)缺乏物理邊界,而這種沒有物理連接的無線通信對于竊聽者來說是開放的,無線通信物理層的安全已經(jīng)成為通信系統(tǒng)安全性的一個關(guān)鍵問題。傳統(tǒng)的安全機制是基于計算復(fù)雜度的安全體系,該體系的設(shè)計思路是加密算法破譯所需的運算能力大于竊聽者實際運算能力。隨著現(xiàn)代計算機運算速度等性能的不斷提升以及竊聽者的運算能力存在極大的不確定性,基于計算復(fù)雜度的安全機制被竊聽者破解的風(fēng)險正在逐漸加大。物理層安全技術(shù)可作為傳統(tǒng)安全機制的重要輔助,也可獨立形成一套基于信息論的安全體系。本論文針對MIMO(Multiple-Input Multiple-Output)系統(tǒng)并結(jié)合信息理論,研究信號發(fā)射前的預(yù)編碼技術(shù),以強化物理層傳輸?shù)陌踩��？諘r編碼是一組實用的信號設(shè)計技術(shù)旨在接近理論極限MIMO信道的容量�？諘r編碼的基本原理和相關(guān)MIMO信號處理很快就演變成一個無線通訊的最有活力的領(lǐng)域。該論文中以空時編碼的性能研究以及擴展型的正交空時碼在MIMO wiretap channel下的安全性能為研究對象。本論文接著研究了Wyner竊聽信道邏輯模型。Wyner介紹了竊聽通道,其中發(fā)射端在存在竊聽者的情況下通過主信道向合法接收者發(fā)送保密信息,竊聽者通過竊聽信道實現(xiàn)竊聽。Wyner曾經(jīng)證明過如果竊聽端的信道相比于主信道更差的情況下,合法接受端可以以不需要公共密鑰的形式接收保密信息,從而秘密容量就可以實現(xiàn)。實際上竊聽者的信道不一定比合法接收者的信道性能更差。如何設(shè)計建立合法通信雙方的信道比竊聽者的信道性能更好的信道模型將是實現(xiàn)無條件秘密通信的重要問題。這也是該論文將要解決的問題。為了確保在MIMO信道上的全速率全分集優(yōu)勢,本文研究了擴展型正交空時分組碼。為了進一步提高接收端信噪比SNR,本文研究了2比特反饋方案的擴展型正交空時分組碼。在該論文中,首先本文歸納了擴展型的正交空時塊碼并將其應(yīng)用到雙向MIMO wiretap channel中。然后基于歸納化擴展型正交空時塊碼,本文提出了一個簡單的部分反饋方案�；跉w納化的擴展型正交空時塊碼和部分反饋方案,合法接收端相對于竊聽端可以獲得更高的信噪比SNR。因此,具有反饋的雙向MIMO wiretap channel的保密容量能夠被極大的擴大。
[Abstract]:The broadcast nature of wireless communication makes the wireless network lack physical boundaries, and this kind of wireless communication without physical connection is open to eavesdroppers. The security of the physical layer of wireless communication has become a key issue in the security of communication systems. The design idea of the system is that the encryption algorithm needs more computing power than the eavesdropper does. With the improvement of the performance of modern computer and so on, there is great uncertainty about the eavesdropper's computing ability. The security mechanism based on computational complexity is becoming more and more vulnerable to eavesdropping. Physical layer security technology can be used as an important aid of traditional security mechanism. In this paper, we study the pre-coding technology before signal transmission for MIMO(Multiple-Input Multiple-Output (MIMO(Multiple-Input) system and information theory. Space-time coding is a set of practical signal design techniques designed to approach the theoretical limit of the capacity of MIMO channels. The basic principle of space-time coding and related MIMO signal processing quickly evolved into a wireless. The most dynamic field of communication. In this paper, the performance of space-time coding and the security performance of extended orthogonal space-time codes under MIMO wiretap channel are studied. The thesis then studies the channel logic model of Wyner eavesdropping. The eavesdropping channel is introduced. In the case of eavesdropping, the transmitter sends confidential information to the legitimate receiver through the main channel. The eavesdropper has proved that if the eavesdropping channel is worse than the primary channel, the eavesdropping channel is worse than the main channel. The legitimate recipient may receive confidential information in a manner that does not require a public key, So the secret capacity can be realized. In fact, the channel of eavesdropper is not necessarily worse than that of the legitimate receiver. How to design the channel model of both sides of legal communication is better than the channel performance of eavesdropper. It is an important problem to realize unconditional secret communication. This is also the problem to be solved in this paper. In order to ensure the advantage of full rate full diversity in MIMO channel, In this paper, the extended orthogonal space-time block codes are studied. In order to further improve SNR of the receiver, the extended orthogonal space-time block codes with 2-bit feedback scheme are studied. In this paper, the extended orthogonal space-time block codes are first summarized and applied to bi-directional MIMO wiretap channel, and then based on inductive extended orthogonal space-time block codes, In this paper, a simple partial feedback scheme is proposed. Based on generalized orthogonal space-time block codes and partial feedback schemes, the SNR of lawful receiver is higher than that of eavesdropping. The security capacity of two-way MIMO wiretap channel with feedback can be greatly expanded.
【學(xué)位授予單位】：東華大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN919.3;TN918

【參考文獻】

相關(guān)碩士學(xué)位論文 前1條

1 黃崇炯;基于MIMO的竊聽信道建模[D];電子科技大學(xué);2010年

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本文編號：1506139