本文選題：信道模型　切入點(diǎn)：多輸入多輸出　出處：《南京信息工程大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：近些年,迅速增長的無線通信業(yè)務(wù)需求使得無線通信系統(tǒng)在不斷地進(jìn)行改進(jìn)。而在無線通信系統(tǒng)設(shè)計(jì)中,無線信道建模占據(jù)重要位置,是建立高品質(zhì)的無線通信系統(tǒng)必要前提。MIMO (Multiple Input Multiple Output)技術(shù)由于能夠有效的解決無線頻譜有限性問題及提高信道容量的優(yōu)勢已引起廣泛關(guān)注,但是該系統(tǒng)的性能受無線衰落信道以及接收與發(fā)射端天線陣列牽制。另外,信號(hào)傳播好壞與無線信道的特性相關(guān),所以建立有效而準(zhǔn)確的信道模型十分重要。本文主要基于幾何空間域信道建模及MIMO系統(tǒng)性能分析,主要有以下幾個(gè)部分:首先,介紹了信號(hào)在無線信道中傳輸時(shí)遇到的大尺度衰落和小尺度衰落,主要介紹了兩種衰落的類別和特點(diǎn),并舉出相應(yīng)信道模型進(jìn)行說明;并且又詳細(xì)的介紹了常用信道模型:高斯衰落模型、瑞利衰落模型、萊斯衰落模型。其次,提出一種更適合描述宏小區(qū)移動(dòng)通信環(huán)境的信道模型,通常在宏小區(qū)環(huán)境中基站處天線要高于附近全部建筑物來降低多徑效應(yīng)的影響,但是實(shí)際情況并非如此,因此根據(jù)這種情況建立更準(zhǔn)確有效的信道模型。在該模型中,散射體采用高斯分布,并且分析了到達(dá)角度(Angle of Arrival,AOA)、到達(dá)時(shí)間(Time of Arrival,TOA)以及多普勒頻移概率密度分布情況。仿真分析結(jié)果與其他模型比較,表明了該模型更適合描述實(shí)際情況中宏小區(qū)移動(dòng)通信環(huán)境。然后,對(duì)于上述信道模型進(jìn)行再一次的改進(jìn),面對(duì)移動(dòng)通信空間環(huán)境是非對(duì)稱性的情況,提出一種更符合實(shí)際情況的非對(duì)稱空間信道模型。此模型不僅可以準(zhǔn)確地描述信號(hào)傳播環(huán)境非對(duì)稱時(shí)信道的重要空時(shí)參數(shù),還應(yīng)用于MIMO接收系統(tǒng)信道性能仿真中,通過分析線性天線陣列和圓形天線陣列下數(shù)值仿真結(jié)果,發(fā)現(xiàn)圓形天線陣列相對(duì)更有優(yōu)勢。接著,本文提出一種適用于室內(nèi)微小區(qū)移動(dòng)通信環(huán)境中的三維(Three Dimensional,3D)空間MIMO信道模型,從二維分析擴(kuò)展至三維空間域分析,增加了波達(dá)信號(hào)在豎直平面上傳播特性。在該模型中,移動(dòng)臺(tái)周圍不存在散射體,且此處看作為中心原點(diǎn),還在基站處放置指向性天線。推導(dǎo)出了該空間信道模型在兩個(gè)不同平面上的重要空時(shí)信道參數(shù),如AOA和TOA的概率密度函數(shù)。通過仿真結(jié)果的對(duì)比,該MIMO信道模型能夠較好的適用于室內(nèi)微小區(qū)的移動(dòng)通信環(huán)境中,為三維空間域信道研究提供了靈活多變的模型。最后基于三維空間域,提出了一種雙筒型的理論信道新模型。由于散射體非均勻分布會(huì)使理論分析變得復(fù)雜且不易得到閉合解析式,因此假設(shè)散射體均勻分布于三維空間域中。該模型能夠準(zhǔn)確地描述室外宏小區(qū)環(huán)境下空間信道的重要空時(shí)參數(shù),推導(dǎo)出了 AOA、TOA的概率分布函數(shù),以及推導(dǎo)出三維空間域下多普勒頻移(Doppler Shift,DS)概率分布函數(shù)。仿真結(jié)果表明,該三維空間域信道模型比二維信道模型更好更準(zhǔn)確的描述了室外宏小區(qū)移動(dòng)通信環(huán)境。
[Abstract]:In recent years, the rapidly growing demand for wireless communication services has led to the continuous improvement of wireless communication systems, and wireless channel modeling plays an important role in the design of wireless communication systems. The technology of multiple Input Multiple output, which is a necessary prerequisite for the establishment of high quality wireless communication systems, has attracted wide attention due to its advantages of effectively solving the problem of limited wireless spectrum and increasing the channel capacity. However, the performance of the system is constrained by the wireless fading channel and the antenna array at the receiver and transmitter. In addition, the quality of the signal propagation is related to the characteristics of the wireless channel. Therefore, it is very important to establish an effective and accurate channel model. This paper mainly based on geometric space domain channel modeling and MIMO system performance analysis, mainly includes the following parts: first, This paper introduces the large scale fading and small scale fading when the signal is transmitted in the wireless channel, mainly introduces the types and characteristics of the two kinds of fading, and gives the corresponding channel model to explain. It also introduces the common channel models in detail: Gao Si fading model, Rayleigh fading model and Rice fading model. Secondly, a channel model which is more suitable to describe the macro cell mobile communication environment is proposed. Usually, in macro cell environment, the antenna at base station is higher than all buildings nearby to reduce the effect of multipath effect, but this is not the case, so a more accurate and effective channel model is established according to this condition. The scatterer is distributed by Gao Si, and the distribution of angle of arrival angle of Arrivalan AOAA, time of arrival time of Arrivalo toa) and Doppler frequency shift probability density are analyzed. The simulation results are compared with other models. The results show that the model is more suitable to describe the mobile communication environment of macro cell in the actual situation. Then, the above channel model is improved once more, and the mobile communication space environment is asymmetric. A more practical asymmetric spatial channel model is proposed, which can not only accurately describe the important space-time parameters of asymmetric channel in signal propagation environment, but also be used in channel performance simulation of MIMO receiving system. By analyzing the numerical simulation results of linear antenna array and circular antenna array, it is found that circular antenna array has more advantages. Then, a three-dimensional three dimensional spatial MIMO channel model suitable for indoor micro-cell mobile communication environment is proposed. In this model, there is no scatterer around the mobile station, which is regarded as the central origin, which is extended from the two-dimensional analysis to the three-dimensional spatial analysis, and the propagation characteristics of the arrival signal in the vertical plane are increased. The important space-time channel parameters of the spatial channel model in two different planes, such as the probability density function of AOA and TOA, are derived. The MIMO channel model can be applied to the mobile communication environment of indoor microcell, and provides a flexible and changeable model for the research of 3D spatial channel. Finally, based on the 3D spatial domain, In this paper, a new theoretical channel model is proposed. The theoretical analysis is complicated and the closed analytical formula is not easy to be obtained due to the nonuniform distribution of scatterers. This model can accurately describe the important space-time parameters of spatial channel in the environment of outdoor macro cell, and derive the probability distribution function of AOAOTOA. The probability distribution function of Doppler shift shift DSs in 3D space is derived. The simulation results show that the 3D channel model is better and more accurate than the two-dimensional channel model in describing the outdoor macro cell mobile communication environment.
【學(xué)位授予單位】：南京信息工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN919.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 李大為;;基于無線移動(dòng)信道建模與仿真技術(shù)探究[J];無線電通信技術(shù);2013年02期

2 張璽君;王繼曾;;移動(dòng)無線信道中多徑衰落的特性分析[J];甘肅科學(xué)學(xué)報(bào);2008年04期

相關(guān)博士學(xué)位論文 前1條

1 李忻;新一代無線通信系統(tǒng)中的MIMO信道建模與多天線設(shè)計(jì)研究[D];電子科技大學(xué);2005年

，

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