【摘要】：隨著蜂窩移動通信系統(tǒng)的發(fā)展,切換將是移動用戶在移動過程中實(shí)現(xiàn)無縫的鏈路連接、得到良好的用戶體驗(yàn)的重要保障。而在LTE系統(tǒng)中,高速的數(shù)據(jù)傳輸率和多媒體服務(wù)需求要求切換能更快速而有效的完成。由于LTE的網(wǎng)絡(luò)結(jié)構(gòu)以及覆蓋特性與2G、3G的不同,切換性能的影響因素也更加多樣化,其中切換門限的選取就是一個值得研究的重要因素�？紤]到小區(qū)的覆蓋特性以及用戶自身的相關(guān)特征,對所有切換事件設(shè)置相同的切換門限是非常不合理的。因此,基于LTE的網(wǎng)絡(luò)覆蓋特性和切換技術(shù),本文主要對公網(wǎng)中的不同移動速度和不同小區(qū)類型以及鐵路專網(wǎng)中的切換門限設(shè)置做了相關(guān)研究,以優(yōu)化切換性能。 論文主要內(nèi)容安排如下,首先總結(jié)分析了LTE系統(tǒng)中的小區(qū)覆蓋性能；然后詳細(xì)介紹了LTE系統(tǒng)中的切換技術(shù),包括切換流程、切換觸發(fā)事件、切換信令流程和切換門限參數(shù),并總結(jié)了現(xiàn)有的切換策略；接下來重點(diǎn)研究了公網(wǎng)中相同切換門限參數(shù)下不同移動速度和服務(wù)小區(qū)類型對切換性能的影響,并在此基礎(chǔ)上通過仿真分析鏈路連接失敗概率和乒乓切換概率來研究設(shè)置合理的切換門限參數(shù)；最后,介紹了高鐵環(huán)境下LTE網(wǎng)絡(luò)覆蓋特性,并提出了一種用速度傳感器捕獲列車位置信息來輔助切換、修改切換門限的切換機(jī)制,主要思想是通過速度傳感器感知列車的實(shí)時速度來計算列車與eNodeB間的距離,并向源eNodeB報告,從而實(shí)現(xiàn)列車位置輔助的切換。同時,通過仿真比較了位置輔助和傳統(tǒng)切換算法的切換發(fā)生概率和切換中斷概率,結(jié)果表明速度傳感器的位置輔助切換能夠幫助減少高速引起的乒乓切換。
[Abstract]:With the development of cellular mobile communication system, handoff will be an important guarantee for mobile users to realize seamless link connection and get a good user experience. In LTE system, high speed data transmission rate and multimedia service requirement require switching to be completed more quickly and effectively. Because the network structure and coverage characteristics of LTE are different from that of 2GN 3G, the influence factors of handoff performance are more diversified, among which the selection of handoff threshold is an important factor worth studying. Considering the coverage characteristics of the cell and the related characteristics of the user itself, it is very unreasonable to set the same handover threshold for all handover events. Therefore, based on the network coverage characteristics and handoff technology of LTE, this paper mainly studies the different moving speeds and different cell types in the public network, as well as the handover threshold setting in the railway private network, in order to optimize the handoff performance. The main contents of this paper are as follows: firstly, the cell coverage performance in LTE system is summarized and analyzed, and then the handover technology in LTE system is introduced in detail, including handover process, handoff trigger event, handover signaling flow and handover threshold parameters. Then, the effects of different speed and cell type on handoff performance under the same handoff threshold parameters in public network are studied. On this basis, through the simulation analysis of link connection failure probability and ping-pong switching probability, the reasonable switching threshold parameters are studied. Finally, the coverage characteristics of LTE network under high-speed rail environment are introduced. A switching mechanism is proposed in which the train position information is captured by the speed sensor and the switch threshold is modified. The main idea is to calculate the distance between the train and the eNodeB by using the speed sensor to perceive the real time speed of the train. And report to the source eNodeB, so as to achieve the train position assist switching. At the same time, the switching probability and interrupt probability of position assistant and traditional handoff algorithm are compared by simulation. The results show that the position-assisted switching of speed sensor can help to reduce the ping-pong switch caused by high speed.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN929.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 肖清華;楊春德;張X;;TD-LTE覆蓋能力綜合分析[J];郵電設(shè)計技術(shù);2012年01期

2 沈嘉;;3GPP LTE物理層標(biāo)準(zhǔn)化最新進(jìn)展[J];移動通信;2007年12期

3 羅凡云;郭俊峰;;TD-LTE網(wǎng)絡(luò)覆蓋性能分析[J];移動通信;2010年05期

4 郭軍偉;;高速移動列車無線組網(wǎng)方案[J];中興通訊技術(shù);2010年02期

，

本文編號：2167776