本文關(guān)鍵詞： 混沌理論 自適應(yīng)參數(shù)辨識 保密通信 復(fù)雜網(wǎng)絡(luò)　出處：《北京郵電大學》2014年博士論文　論文類型：學位論文

【摘要】：隨著信息技術(shù)的飛速發(fā)展和大數(shù)據(jù)時代的到來,人們在享受網(wǎng)絡(luò)帶來更多便利的同時,越來越多的數(shù)據(jù)和信息在傳輸過程中也面臨著監(jiān)聽、竊取、惡意篡改等威脅。信息安全問題成為這個時代影響國家安全和社會發(fā)展的重大問題,現(xiàn)有的保密通信方法面臨著越來越多的挑戰(zhàn),研究新的保密通信方法來保護信息和數(shù)據(jù)的安全通信成為通信、計算機、信息等相關(guān)領(lǐng)域中的前沿和熱點方向之一。 混沌信號由于具有對初始條件的敏感性、非周期性、類噪聲性、連續(xù)寬帶頻譜等固有屬性,使其具有高度的不可預(yù)測性和天然的隱蔽性,特別適合作為保密通信中的傳輸載體。二十世紀九十年代初,混沌保密通信的想法一經(jīng)問世,便成為信息安全領(lǐng)域研究的熱點問題,國內(nèi)外科學家和研究人員從信息的加密算法、抗攻擊性、混沌器件等不同角度對混沌保密通信模型及其相關(guān)技術(shù)展開了深入研究。如今在大數(shù)據(jù)時代的影響下,混沌保密通信的研究方向也開始向著數(shù)字化、多用戶、高性能、寬帶無線等方面發(fā)展。 通常情況下,混沌保密通信模型中的混沌系統(tǒng)存在著部分參數(shù)未知或全部參數(shù)未知的情況,這種未知性盡管會使得系統(tǒng)更難操作和控制,卻會給利用這些參數(shù)進行信息調(diào)制的方法帶來更高的安全性,提高了通信過程的保密性。為了更好地操作這類系統(tǒng)并實現(xiàn)信息的加密,可以將非線性控制理論中的自適應(yīng)參數(shù)辨識技術(shù)引入帶有未知參數(shù)的混沌系統(tǒng),通過對系統(tǒng)狀態(tài)或輸出的不斷測量,與預(yù)期目標進行比較,根據(jù)這個差值調(diào)整系統(tǒng)的結(jié)構(gòu)或參數(shù)以實現(xiàn)控制的作用,周而復(fù)始直至達到最終目標。 本論文研究了混沌系統(tǒng)的自適應(yīng)參數(shù)辨識技術(shù)及其在保密通信中的應(yīng)用,主要創(chuàng)新工作歸納如下： (1)本論文提出了一個自適應(yīng)參數(shù)辨識中的新型判定條件——格拉姆矩陣條件,這個條件的提出建立了持續(xù)激勵條件和線性無關(guān)條件之間的橋梁。持續(xù)激勵條件或線性無關(guān)條件是自適應(yīng)參數(shù)辨識中應(yīng)用廣泛的兩個基本條件,但是它們之間的關(guān)系一直懸而未決。不同于這兩個條件的計算方法,所提出的格拉姆矩陣條件通過計算矩陣的秩來判斷未知參數(shù)的收斂情況,在某些情況下,能夠降低計算持續(xù)激勵條件或線性無關(guān)條件時的運算量,更具有實用性和高效性。 (2)本論文指出了近年來多篇自適應(yīng)參數(shù)辨識文章中在設(shè)計辨識方法時的錯誤。傳統(tǒng)線性無關(guān)條件的定義中缺少了對時間的限制,對于一個隨時間變化的函數(shù),無法通過普通的線性無關(guān)定義判斷其相關(guān)性。本論文提出了持續(xù)激勵條件、線性無關(guān)條件或格拉姆矩陣條件在長時間和有限時間情況下的相關(guān)定義,由此分析了混沌系統(tǒng)同步過程和判定條件持續(xù)時間長短對辨識結(jié)果的影響。除此之外,本論文提出了在噪聲存在情況下參數(shù)辨識的方法,以及降低噪聲干擾的措施。這部分中提出的判定條件和方法都可以應(yīng)用在混沌保密通信方案中。 (3)本論文提出了一種基于自適應(yīng)參數(shù)辨識的混沌通信模型,在一維標量混沌信號中加載了多個信息,實現(xiàn)了多信息的混沌保密通信傳輸。在這種通信模型中,原始信息首先被直接調(diào)制在發(fā)送端帶有多個時滯的標量混沌系統(tǒng)的參數(shù)中,在接收端通過自適應(yīng)參數(shù)辨識的方法對加載在混沌信號中的信息進行解調(diào)。這個由一維混沌系統(tǒng)構(gòu)造的混沌通信模型攜帶的信息量比傳統(tǒng)混沌通信模型攜帶的信息量多得多并且系統(tǒng)更加簡單。接著,基于沃爾什函數(shù)構(gòu)成的正交基,本論文將多路原始信息與沃爾什序列進行正交調(diào)制,再加載在發(fā)送端的混沌系統(tǒng)參數(shù)中,更大程度地提高了系統(tǒng)攜帶的信息總量。本論文所提出的混沌保密通信方案在混沌激光通信領(lǐng)域有潛在的應(yīng)用前景。 (4)本論文提出了一種利用混沌同步暫態(tài)過程實現(xiàn)復(fù)雜動態(tài)網(wǎng)絡(luò)系統(tǒng)結(jié)構(gòu)辨識的方法。前面研究了兩個混沌系統(tǒng)構(gòu)成的混沌保密通信方案,實現(xiàn)了點對點的混沌通信傳輸。多個混沌通信系統(tǒng)相互通信就構(gòu)成了復(fù)雜動態(tài)網(wǎng)絡(luò)的結(jié)構(gòu)。近年來研究復(fù)雜動態(tài)網(wǎng)絡(luò)的文章普遍認為網(wǎng)絡(luò)內(nèi)部的同步現(xiàn)象阻礙拓撲結(jié)構(gòu)辨識的完成。而本論文深入探索了網(wǎng)絡(luò)同步的暫態(tài)過程,利用所提出的自適應(yīng)參數(shù)辨識方法研究復(fù)雜網(wǎng)絡(luò)內(nèi)部節(jié)點間的拓撲連接,發(fā)現(xiàn)只要系統(tǒng)有足夠的時間和能量驅(qū)動網(wǎng)絡(luò)收斂到真值,即使隨后網(wǎng)絡(luò)達到了同步狀態(tài),網(wǎng)絡(luò)辨識的結(jié)果也不會再發(fā)生改變,在這種情況下網(wǎng)絡(luò)同步并沒有阻礙結(jié)構(gòu)的辨識。
[Abstract]:With the rapid development of the times and the data of information technology is coming, people enjoy the network to bring more convenience, more and more data and information in the transmission process is also faced with monitoring, theft, tampering and other threats. The issue of information security has become a major problem in this age affect the national security and social development, secure communication the existing methods are facing more and more challenges, the new research method of secure communication to protect the security of information and data communication become the communications, computer, information and other related fields in the frontier and hot direction.
Chaotic signal has the sensitivity to initial conditions, non periodic, noise, continuous broadband spectrum property, which has a high degree of unpredictability and natural concealment, especially as the carrier of secure communication. At the beginning of 1990s, the idea of chaotic secure communication was developed, will become hot issues in the field of information security, domestic and foreign scientists and researchers from the information encryption algorithm, robustness, different angles of chaotic devices done in-depth research on chaotic secure communication model and its related technology. Now in the era of big data, the research direction of chaotic secure communication towards the digital, multi user high performance broadband, wireless, and other aspects of development.
Typically, chaotic system, chaotic secure communication model exists in part or all of the parameters of unknown parameters is unknown, this is unknown although will make the system more difficult to operate and control methods, it will be for information modulation by using these parameters to bring more security, improve the security of communication in order to process. Better operation of this kind of system and the realization of information encryption, can be adaptive parameter identification of nonlinear control theory in the introduction of chaotic systems with unknown parameters, through continuous measurement of the system state or output, compared with the expected target, according to the structure and the parameter of this difference adjustment system to realize the control function, until the cycle to achieve the ultimate goal.
In this paper, the adaptive parameter identification technology of chaotic system and its application in secure communication are studied. The main innovation work is summarized as follows:
(1) this paper proposes an adaptive parameter identification in new condition - Gram matrix condition, put forward the conditions established between persistent excitation condition and linear independence condition of the bridge. The persistent excitation condition or linear independence condition are two basic conditions for wide application of adaptive parameter identification, but the relationship between them has been in suspense. The calculation method is different from the two conditions, convergence of Gram matrix condition proposed by calculating the rank of matrix to determine the unknown parameters, in some cases, can reduce low computation calculation of persistent excitation condition or linear independence condition, more practical and efficient.
(2) this paper pointed out that in the design of identification error when many articles in the article. The definition of adaptive parameter identification in traditional linear independent conditions for the lack of the time limit for a time-varying function, not by ordinary linear independent definition and judge the correlation. This thesis presents the persistent excitation condition the definition, linear independence condition or Gram matrix condition in long time and limited time conditions, the influence of the synchronization process of chaotic system and the criteria for the duration of the identification results. Besides, this paper puts forward the method of parameter identification under the presence of noise, and measures to reduce noise. To determine the conditions and the method proposed in this part can be used in chaotic secure communication scheme.
(3) this paper presents a model of adaptive chaotic communication based on parameter identification, the one-dimensional Scalar Chaotic signal to load multiple information, realize the chaotic secure communication transmission of information. In this communication model, the original information is first parameter Scalar Chaotic System of direct modulation in the transmitter with multiple delay in the demodulation of loading in chaos signal information at the receiver through the method of adaptive parameter identification. This is carried by the one-dimensional chaotic communication model of chaotic system structure of the information carrying amount of information system and much more than the traditional chaotic communication model is more simple. Then, based on the orthogonal basis of Walsh function, the the orthogonal modulation multiple original information and Walsh sequence, chaotic system parameters and loading at the transmitting end, greatly improve the system to carry the information The chaotic secure communication scheme proposed in this paper has potential applications in the field of chaotic laser communication.
(4) this paper presents a method of using chaotic synchronization to realize the transient process of complex dynamic network system structure identification. The research of chaotic secure communication scheme composed of two chaotic systems, the chaotic communication transmission point-to-point. Multiple chaotic communication system mutual communication constitute the structure of complex dynamical networks the study of complex dynamic network. In recent years the article generally believe that the synchronization phenomenon within the network topology identification is completed hinder. This paper explores the transient process of network synchronization, using the method of parameter identification of the adaptive research of complex network topology the internal links between the nodes, the system found that as long as there is enough time and energy to drive network converge to the true value, then even if the network has reached the synchronization state, network identification results will not change, in this case the network synchronization and There is no hindrance to the identification of the structure.

【學位授予單位】：北京郵電大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TN918;O415.5

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相關(guān)期刊論文 前1條

1 方錦清;;混沌通信及其相關(guān)網(wǎng)絡(luò)信息安全研究的若干進展[J];系統(tǒng)工程學報;2010年06期

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本文編號：1548185