本文選題：隧道 + 射線跟蹤�。� 參考：《北京交通大學》2017年碩士論文

【摘要】：隨著城市規(guī)模擴大和人口數(shù)量增加,地鐵已經(jīng)成為城市居民出行的主要交通工具,同時便攜式通信設備的普及使得人們對出行時的通信需求越來越高。在地下軌道交通中,隧道是一種主要場景,而隧道與開放環(huán)境下的信道特征截然不同。隧道作為一種受限空間,其電波傳播會存在各種反射、透射、折射,以及鎖孔效應,導致信道惡化。為了建立高效可靠的無線通信系統(tǒng),需要對隧道環(huán)境下無線信道特性進行深入研究。本團隊在北京交通大學隧道中心和江蘇南通中天科技集團隧道實驗室進行了兩次實際測量,并使用射線跟蹤法對實際測量場景進行仿真。通過對比大尺度衰落特性,發(fā)現(xiàn)仿真結果與實測結果有較高的一致性,二者均方根誤差約為4dB,可以認為射線跟蹤法能夠對隧道環(huán)境下大尺度衰落進行準確預測。通過對比信道沖激響應,發(fā)現(xiàn)實測與仿真結果在時延和衰落上有較好的吻合度,因此可以認為使用射線跟蹤法仿真得到的信道沖激響應是準確的。通過射線跟蹤法對隧道模型進行擴展仿真。在文中構建的隧道下,2.4GHz和5.9GHz的路徑損耗指數(shù)分別為1.418和1.438,陰影衰落服從正態(tài)分布。對比長直隧道和彎曲隧道下的路徑損耗,結果表明彎曲隧道的路徑損耗比長直隧道略大。發(fā)射天線位于彎曲隧道內(nèi)側時比位于外側時路徑損耗大,并且兩者的差值與收發(fā)天線之間的距離成正比。多天線技術是提高信道容量的重要技術,對比單天線與2×2天線,結果表明多天線可以很大程度上提高容量。本文引進車體模型,研究車體對MIMO系統(tǒng)的影響,與無車體的情況相比,有車體時接收端角度擴展較大,天線之間的相關性較小,容量較大。隨著天線數(shù)目的增加,信道容量增加明顯,但無車時信道容量與瑞利信道容量的差值隨天線數(shù)目的增加急劇變大,而有車情況下差值變化不顯著。當天線間隔增大時無車情況下的信道容量增大,有車的情況下并沒有明顯的變化。
[Abstract]:With the expansion of the city scale and the increase of population, subway has become the main means of transportation for urban residents, and the popularity of portable communication equipment makes people more and more need to travel. In underground rail transit, tunnel is a main scene, and the channel characteristics of tunnel and open environment are very different. As a limited space, the propagation of radio waves in a tunnel will have a variety of reflection, transmission, refraction, and keyhole effect, which leads to the deterioration of the channel. In order to establish an efficient and reliable wireless communication system, it is necessary to study the wireless channel characteristics in tunnel environment. The team conducted two actual measurements at the Tunnel Center of Beijing Jiaotong University and the Tunnel Laboratory of Jiangsu Nantong Zhongtian Science and Technology Group and simulated the actual measurement scene by ray tracing method. By comparing the characteristics of large-scale fading, it is found that the simulation results are in good agreement with the measured results, and the root-mean-square error between them is about 4 dB. It can be considered that the ray tracing method can accurately predict the large-scale fading in tunnel environment. By comparing the channel impulse response, it is found that the measured results are in good agreement with the simulation results in terms of time delay and fading. Therefore, the channel impulse response simulated by ray tracking method is considered to be accurate. The extended simulation of tunnel model is carried out by ray tracing method. The path loss exponents of the tunnel constructed in this paper are 1.418 and 1.438 at 2.4 GHz and 1.4 38, respectively, and the shaded fading suits are distributed from normal to normal. The results show that the path loss of the curved tunnel is slightly larger than that of the long straight tunnel. The path loss of the transmitting antenna is larger when it is located inside the curved tunnel than at the outside, and the difference between them is proportional to the distance between the transmitting and receiving antennas. Multi-antenna technology is an important technique to improve the channel capacity. Compared with single antenna and 2 脳 2 antenna, the results show that multi-antenna can improve the capacity to a large extent. In this paper, a carbody model is introduced to study the effect of car-body on MIMO system. Compared with car-body, the angle expansion of the receiving end is larger, the correlation between antennas is smaller and the capacity is larger when there is a car-body. With the increase of the number of antennas, the channel capacity increases obviously, but the difference between the channel capacity and Rayleigh channel capacity increases sharply with the increase of the number of antennas, but the difference does not change significantly with the increase of the number of antennas. When the antenna spacing increases, the channel capacity increases without vehicle, but there is no obvious change in the case of vehicle.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN92

【參考文獻】

相關期刊論文 前10條

1 甘雯雯;陶成;劉留;周濤;孫溶辰;;地鐵隧道環(huán)境下2.4 GHz頻段路徑損耗特性[J];河北大學學報(自然科學版);2015年01期

2 萬有達;劉留;;地下軌道交通無線信息通信與關鍵技術[J];現(xiàn)代電子技術;2013年17期

3 吳彥鴻;王聰;徐燦;;無線通信系統(tǒng)中電波傳播路徑損耗模型研究[J];國外電子測量技術;2009年08期

4 李成杰;裴崢;;無線信號服從瑞利分布的驗證方法[J];通信技術;2009年05期

5 趙國群;朱峰;;地面反射電磁波影響的分析[J];信息通信;2008年05期

6 李彥麗;張義尉;段曉輝;焦秉立;;短波信道相干帶寬的計算[J];北京大學學報(自然科學版);2008年05期

7 李文翔;熊慶國;左韜;;無線信道衰落對移動自組網(wǎng)影響的研究[J];計算機應用與軟件;2008年06期

8 蔣澤,顧朝志;無線信道模型綜述[J];重慶工學院學報;2005年08期

9 武樺 ,賈懷義;橢圓隧道中UHF電波傳播特性[J];微計算機信息;2005年20期

10 季忠,黎濱洪,王豪行,陳興義,趙耀庚;用射線跟蹤法對室內(nèi)電波傳播進行預測[J];電波科學學報;1999年02期

相關博士學位論文 前1條

1 張明;寬帶多天線無線傳播信道的特性、測量和建模研究[D];北京郵電大學;2008年

相關碩士學位論文 前3條

1 李文娟;大規(guī)模多天線信道測量及小尺度衰落特性研究[D];北京交通大學;2016年

2 張靜;隧道環(huán)境下無線信道建模和容量分析[D];北京交通大學;2014年

3 程文璞;高速移動環(huán)境中基于理論方法的無線信道建模研究[D];北京交通大學;2014年

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本文編號：1982859