發(fā)布時間：2018-07-04 21:15

  本文選題：平均距離 + 節(jié)點不相交路徑��； 參考：《電子科技大學(xué)》2014年博士論文

【摘要】：隨著網(wǎng)絡(luò)的快速發(fā)展,越來越多的高清圖片和音視頻應(yīng)用使得網(wǎng)絡(luò)的流量呈指數(shù)增長,而網(wǎng)絡(luò)的建設(shè)遠跟不上網(wǎng)絡(luò)的發(fā)展,因此需要一個高效的網(wǎng)絡(luò)以支撐各種應(yīng)用和業(yè)務(wù)的開展。電子商務(wù)、在線支付等應(yīng)用的飛速發(fā)展要求網(wǎng)絡(luò)要具有較好的實時性;而各種自然災(zāi)害、攻擊和破壞要求網(wǎng)絡(luò)能夠應(yīng)對各種故障,因此一個高效可靠的網(wǎng)絡(luò)拓撲和傳輸機制顯得十分重要。網(wǎng)絡(luò)拓撲是網(wǎng)絡(luò)高效、可靠傳輸?shù)幕A(chǔ),故障恢復(fù)用來保護網(wǎng)絡(luò)的可靠傳輸,高效的傳輸機制保證信息的高效傳輸,高效可靠的網(wǎng)絡(luò)拓撲和高效的傳輸機制共同促進整個網(wǎng)絡(luò)的高效可靠運行。本文在詳細分析網(wǎng)絡(luò)拓撲優(yōu)化、故障保護以及基于無速率碼的傳輸?shù)确矫嫜芯楷F(xiàn)狀的基礎(chǔ)上,指出進一步提高網(wǎng)絡(luò)高效可靠需要研究的問題,針對這些問題,本文在高效可靠網(wǎng)絡(luò)拓撲優(yōu)化、鏈路故障保護、高效無速率碼設(shè)計等方面展開了一系列研究,并在以下幾個方面取得了一些有價值的研究成果:1.高效網(wǎng)絡(luò)拓撲優(yōu)化設(shè)計在給定節(jié)點和鏈路數(shù)量下,設(shè)計一種基于平均距離的網(wǎng)絡(luò)拓撲優(yōu)化算法。該算法利用網(wǎng)絡(luò)拓撲鄰接矩陣的特點來降低運算量,該算法分兩步實現(xiàn)最佳網(wǎng)絡(luò)拓撲的選擇:第一,通過計算網(wǎng)絡(luò)拓撲的平均距離,算法有可能找到多個具有最小平均距離的網(wǎng)絡(luò)拓撲;第二,進一步計算每個節(jié)點和鏈路故障后的平均距離,并選出故障后平均距離最小的網(wǎng)絡(luò)拓撲作為最優(yōu)的網(wǎng)絡(luò)拓撲。2.節(jié)點之間具有最多節(jié)點不相交路徑和最大節(jié)點連通度的網(wǎng)絡(luò)拓撲設(shè)計提出一種在任意兩個節(jié)點之間具有最多的節(jié)點不相交路徑且具有較高節(jié)點連通度的網(wǎng)絡(luò)模型,設(shè)計了在給定節(jié)點和鏈路數(shù)量下設(shè)計滿足上述模型的算法,并通過采用一些技巧降低運算量。計算結(jié)果表明,該算法所設(shè)計的網(wǎng)絡(luò)既滿足節(jié)點不相交路徑要求又能達到或者接近網(wǎng)絡(luò)的理論節(jié)點連通度。將高效性和可靠性相結(jié)合給出了設(shè)計既具有最多的節(jié)點不相交路徑和較大節(jié)點連通性,又有較小平均距離的網(wǎng)絡(luò)拓撲設(shè)計算法。3.基于網(wǎng)絡(luò)編碼的多鏈路故障保護改進一種基于網(wǎng)絡(luò)編碼的方法實現(xiàn)在相同數(shù)量主路徑情況下用最少的保護路徑實現(xiàn)對多個鏈路故障的保護,該方案不僅考慮主路徑故障的情況,同時也考慮了保護路徑故障的情況。4.無速率碼的性能指標(biāo)及理想模型在分析當(dāng)前無速率碼性能指標(biāo)的缺點和適用范圍的基礎(chǔ)上,提出新的性能指標(biāo),并推廣了傳統(tǒng)系統(tǒng)碼的定義,然后提出一種理想的無速率碼模型來全面描述無速率碼。5.基于兩階段前向等概的無速率碼設(shè)計以理想無速率碼模型為基礎(chǔ),提出一種基于兩階段前向等概的無速率碼設(shè)計算法,仿真結(jié)果表明該算法編出的無速率碼具有較高的碼率、較小的平均延時、較小的最大失序和較大的均勻恢復(fù)熵。將兩階段前向等概編碼算法稍做修改可以用于不等差錯保護,同樣具有上述的性能優(yōu)勢。對于無法知道信道精確狀況但知道其最壞狀況的情形,給出一種在已知最大擦除概率情況下的無速率碼的設(shè)計,仿真表明其性能相比無任何先驗知識的設(shè)計算法性能略有提高。最后分析了編碼算法對譯碼算法的影響,分析表明,該編碼算法可以大大降低高斯消元法和BP譯碼算法的運算量。6.基于環(huán)的高效無速率碼設(shè)計組成一個文件的每個信息符號之間并不是孤立的,而是存在一定的關(guān)聯(lián)性,本文將這種關(guān)聯(lián)性應(yīng)用在無速率的設(shè)計中并結(jié)合高效性提出一種基于環(huán)的高效無速率碼的設(shè)計方案,該方案除了有較好的性能之外,更接近于真實的通信環(huán)境。7.基于效率-公平的無速率碼設(shè)計雖然基于兩階段和前向等概的編碼算法有很好的性能,但該性能只是平均意義下的性能,無法保證每一次通信的性能都能滿足要求。本文通過修正理想無速率碼模型,給出基于新模型的無速率碼設(shè)計算法。該算法基于效率和公平原則,并通過確定性和隨機性相結(jié)合提高性能,仿真結(jié)果表明該算法具有較好的性能。對該算法稍作修改,便可以用于不等差錯保護,同樣具有較好的性能。
[Abstract]:With the rapid development of the network, more and more high-definition pictures and audio and video applications have made the network traffic exponential growth, and the construction of the network is far from the development of the network. Therefore, an efficient network is needed to support the development of various applications and services. The rapid development of electronic commerce, line payment and other applications requires the network to have The network topology and transmission mechanism is very important. The network topology is the basis of high efficient network and reliable transmission, the fault recovery is used to protect the reliable transmission of the network, and the efficient transmission mechanism ensures the information. Efficient transmission, efficient and reliable network topology and efficient transmission mechanism jointly promote the efficient and reliable operation of the whole network. On the basis of detailed analysis of network topology optimization, fault protection and rate based transmission based on rate code transmission, this paper points out that further research on high network efficiency and reliability needs to be studied. Some studies have been carried out in the aspects of efficient and reliable network topology optimization, link failure protection, high efficient rate code design and so on, and some valuable research achievements have been obtained in the following aspects: 1. design a network topology based on the average distance under the given node and the number of chain paths. The algorithm uses the characteristics of the network topology adjacency matrix to reduce the computational complexity. The algorithm divides the optimal network topology into two steps. First, by calculating the average distance of the network topology, it is possible to find a number of network topologies with minimum average distance; second, each node and link fault can be further calculated. The network topology with the best network topology as the optimal network topology, which has the most node disjoint path and the maximum node connectivity, presents a network topology that has the most node disjoint paths between any two nodes and has higher node connectivity among the two nodes. The network model designs the algorithm designed to satisfy the above model under the number of given nodes and links, and reduces the computation by using some techniques. The calculation results show that the network designed by the algorithm not only satisfies the node disjoint path requirements but also can reach or close to the connectivity of the theoretical nodes of the network. The network topology design algorithm,.3., which has the most nodes not intersecting paths, larger nodes connectivity, and smaller average distance, is based on network coded multi link fault protection improvement. A network coding based method is used to implement multiple chains with the least protection path in the same number of main paths. The scheme not only takes into account the failure of the main path, but also considers the performance index of the.4. rate code and the ideal model, based on the analysis of the shortcomings of the current rate code performance index and the scope of application, and extends the definition of the traditional system code, and then the definition of the traditional system code is extended. An ideal rate free code model is proposed to fully describe the rate code.5. based on the two phase forward probability code based on the ideal rate code. Based on the ideal rate free code model, a rate code design algorithm based on the two phase forward equal probability is proposed. The simulation results show that the rate code produced by the algorithm has a high bit rate and is smaller. The average delay, the smaller maximum loss order and the larger uniform recovery entropy. The two phase forward equivalent coding algorithm is modified to be used for unequal error protection. It also has the above performance advantage. For the case where the channel precision is not known but the worst case is known, a given maximum erasure probability is given. The design of the rate free code shows that the performance of the design algorithm is slightly higher than that without any prior knowledge. Finally, the influence of the coding algorithm on the decoding algorithm is analyzed. The analysis shows that the algorithm can greatly reduce the computation of the Gauss elimination and BP decoding algorithm.6. based on the high efficient rate code design based on the loop. Each of the information symbols is not isolated, but there is a certain relevance. In this paper, this relevance is applied to the design of a rate free design and combined with the efficiency of the design. The scheme is more efficient and is closer to the actual communication environment,.7., based on the better performance. The rate fair rate free code design has good performance on the basis of the two phase and forward equivalent coding algorithm, but the performance is only in the mean sense, and the performance of every communication can not be guaranteed. In this paper, a new model based non rate code design algorithm is given by modifying the ideal rate free code model. The method is based on the principle of efficiency and fairness, and improves performance by combining certainty and randomness. The simulation results show that the algorithm has good performance. The algorithm can be used for unequal error protection with slight modification to the algorithm, and it has good performance.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TP393.02
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本文編號：2097452