本文選題：高鐵無線信道 + 隨機傳播圖　； 參考：《北京交通大學(xué)》2014年碩士論文

【摘要】：近年來,我國告訴鐵路(“高鐵”)的迅速發(fā)展受到了國際廣泛關(guān)注,同時也極大的促進了國內(nèi)經(jīng)濟增長。隨之而來的高鐵通信成為了當(dāng)前學(xué)術(shù)界和產(chǎn)業(yè)界的熱點問題�，F(xiàn)有鐵路通信系統(tǒng)已無法滿足未來的高鐵通信需求,新一代鐵路通信系統(tǒng)的研究與開發(fā)勢在必行。眾所周知,信道模型對于無線通信系統(tǒng)的設(shè)計起著至關(guān)重要的作用。大尺度衰落模型可用于網(wǎng)絡(luò)的覆蓋預(yù)測和干擾分析,而小尺度衰落模型則為系統(tǒng)仿真和算法評估提供參考。 本文首先介紹高鐵無線信道電波傳播特性,根據(jù)近年來幾次高鐵信道測量獲得的大尺度傳播模型,總結(jié)歸納了不同場景不同帶寬下的測量結(jié)果,羅列出高鐵不同場景下大尺度衰落特征。同時介紹小尺度衰落特征,分析高鐵無線信道關(guān)鍵參數(shù)(如K因子、多普勒(Doppler)功率譜、多徑功率延遲潛)提取方法。接著,介紹了其中一種情況下信道容量的計算方法,結(jié)合高鐵實際測量數(shù)據(jù),統(tǒng)計分析高鐵不同場景下遍歷容量和中斷容量的變化特征。 接下來本文采用頻域/時域理論分析的模型構(gòu)建方法,建立無線移動通信系統(tǒng)在高速移動場景下的信道模型。(1)基于頻域的隨機傳播圖的信道建模方法,通過將傳播環(huán)境中的反射物和傳播射線抽象為有向圖中的定點和邊,可研究出多個反射體、散射體反射或散射帶來的多次反射特性,最終獲得整個傳播信道的傳遞函數(shù)。同時根據(jù)高鐵實際測量數(shù)據(jù)、利用Von Mises分布模擬接收端到達角等方法,校準(zhǔn)和驗證隨機傳播圖建模方法的可行性和研究價值�；陔S機傳播圖方法對高鐵典型移動場景進行信道建模,根據(jù)仿真得到信道的沖激響應(yīng)(Channel Impulse Response-CIRs)，，分析信道關(guān)鍵參數(shù)信息,討論高鐵移動信道衰落特性。(2)基于時域的幾何隨機散射理論建模,信道特征是基于反射物的散射線在接收端射線迭加獲取。通常,為了時域迭加的方便和簡化數(shù)學(xué)推導(dǎo),這種建模方法在傳播模型抽象圖中假設(shè)無線電波在反射物和散射物反射次數(shù)有限。本文主要重點研究單環(huán)和橢圓模型,深入研究其無線信道時間域和空間域的相關(guān)函數(shù),分別推導(dǎo)空-時相關(guān)函數(shù)的閉合表達式。 目前,高鐵場景下的信道建模主要是基于實際的信道測量數(shù)據(jù)。然而,高鐵信道測量工作開展難度較大,很難獲取足夠的測量數(shù)據(jù)用于信道建模。隨著信道建模理論的發(fā)展,隨機傳播圖和幾何散射理論是兩種可靠、準(zhǔn)確的信道建模方法。為此,本文基于這兩種先進的建模理論構(gòu)建高鐵場景下的信道模型,該模型不僅與實際的測量結(jié)果相匹配,而且能夠用于評估高鐵多天線系統(tǒng)性能。
[Abstract]:In recent years, the rapid development of China's tell railway ("high-speed railway") has received extensive international attention, but also greatly promoted the domestic economic growth. The following high-speed communication has become a hot issue in academia and industry. The existing railway communication system can not meet the needs of future high-speed railway communication, so the research and development of the new generation railway communication system is imperative. As we all know, channel model plays an important role in the design of wireless communication system. The large scale fading model can be used for the coverage prediction and interference analysis of the network, while the small scale fading model can be used as a reference for system simulation and algorithm evaluation. This paper first introduces the characteristics of radio wave propagation in high speed rail wireless channel. According to the large scale propagation model obtained from several high speed railway channel measurements in recent years, the measurement results under different scenarios and different bandwidth are summarized. The characteristics of large scale fading in different scenarios of high-speed train are listed. At the same time, the characteristics of small scale fading are introduced, and the extraction method of key parameters (such as K factor, Doppler Doppler spectrum, multipath power delay submergence) for high speed wireless channel is analyzed. Then, the calculation method of channel capacity in one of the cases is introduced, and the variation characteristics of traversal capacity and interrupt capacity under different scenarios of high-speed rail are analyzed by combining with the actual measurement data of high-speed rail. Then, this paper uses the model construction method of frequency domain / time domain theory analysis to establish the channel model of wireless mobile communication system under high speed mobile scene. (1) the channel modeling method based on random propagation graph in frequency domain. By abstracting the reflectors and propagating rays in the propagation environment into fixed points and edges in the directed graph, the properties of multiple reflectors, scatterers or scattering can be studied. Finally, the transfer function of the whole propagation channel can be obtained. At the same time, the feasibility and research value of the stochastic propagation graph modeling method are calibrated and verified by using the Von Mises distribution to simulate the arrival angle of the receiver according to the actual measurement data of high-speed rail. Based on the stochastic propagation graph method, the channel model of the typical high-speed railway mobile scene is built, and the channel impulse response channel Impulse response to CIRs is obtained by simulation, and the critical channel parameter information is analyzed. In this paper, the fading characteristics of high speed mobile channels are discussed. The model is based on the geometric random scattering theory in time domain. The channel features are obtained by superposition of reflecting-based scattered rays at the receiving end. In order to simplify the mathematical derivation of superposition in time domain, this modeling method assumes in the abstract map of propagation model that the number of reflections of radio waves in reflectors and scatters is limited. In this paper, the single ring and elliptic models are studied, and the correlation functions in time domain and space domain of wireless channel are studied in depth, and the closed expressions of space-time correlation function are derived respectively. At present, the channel modeling in the high-speed train scene is mainly based on the actual channel measurement data. However, it is difficult to obtain enough measurement data for channel modeling. With the development of channel modeling theory, stochastic propagation graph and geometric scattering theory are two reliable and accurate channel modeling methods. Therefore, based on these two advanced modeling theories, this paper constructs the channel model in the high speed train scenario. The model not only matches the actual measurement results, but also can be used to evaluate the performance of the high-speed rail multi-antenna system.
【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】

相關(guān)期刊論文 前1條

1 劉留;陶成;邱佳慧;陳后金;;高速鐵路平原場景無線信道小尺度衰落特征的研究[J];鐵道學(xué)報;2012年05期

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