基于IEEE802.11标准的MIMO信道建模与分析

发布时间：2018-04-07 19:04

本文选题：无线局域网　切入点：802.11n　出处：《西南交通大学》2014年硕士论文

【摘要】：随着移动通信的快速发展,现在对通信系统的带宽,容量以及通信质量等的要求越来越高,而能满足上述要求的关键技术之一正是多输入多输出(MIMO, Multiple-Input and Multiple-Out)技术。MIMO技术是实现高数据速率、大系统容量、高传输质量的空间分集技术,因此MIMO技术将非常有可能成为未来高速移动通信系统中的重点研究的通信技术之一,并将发挥出特有的优势。在MIMO系统中,若各接收天线信号不相关,则可以较好的提高系统的抗衰落性,并且能通过增加天线数目来提高系统容量,可以极大的提高频谱利用率。但是由于天线之间的间隔不可能无限大,所以各条路径上的接收信号之间就势必会具有一定的相关性。因此为了更深入地研究MIMO技术和评估系统性能的好坏以及算法的优劣,有必要研究MIMO信道特性,并建立适合相应场景的信道模型。首先,本文介绍了宽带无线信道模型的研究成果和有待解决的问题。分析了无线衰落信道的特性、大尺度衰落、小尺度衰落以及其包络特性。其中重点介绍了MIMO信道中关注的小尺度衰落。其次,对无线信道建模的基本理论知识做了相关介绍,包括：无线信道建模的关键参数、MIMO信道建模的分类、典型的MIMO空间信道模型以及MIMO信道空间相关性。从相关矩阵和相关系数两方面分析了MIMO信道的相关性,考虑了高斯分布、均匀分布以及拉普拉斯分布这三种接收信号可能的角度功率谱分布,详细的给出了相应的信道空间相关系数的计算公式,并进行了仿真。结果表明影响天线之间的相关性因素主要有：天线间隔、到达角(AOA, Angle Of Arrival)、离开角(AOD, Angle Of Departure)、角度扩展(AS, Angular Spread)和角度功率谱(PAS, Power Azimuth Spectrum)等。最后,详细阐述了信道模型参数,具体刻画了TGn MIMO信道的具体实现过程,并且给出了信道模型的详细仿真思路和仿真流程,对信道模型的特性如、时域响应、累积分布函数图、功率时延谱、多普勒频移以及相关性等进行了分析和验证。表明了该信道模型的合理性,符合无线局域网的实际传播环境。将信道模块加入系统进行整体的仿真,比较了不同天线配置、不同信道模型下的PER性能,得出了一些参考结论；最后考虑了在高速环境下基于上述模型的信道建模,仿真了其信道特性,验证了模型的合理性。
[Abstract]:With the rapid development of mobile communication, the requirements of bandwidth, capacity and communication quality of communication system are becoming higher and higher.One of the key technologies that can meet the above requirements is Multiple-Input and Multiple-Out.MIMO, which is a spatial diversity technology with high data rate, large system capacity and high transmission quality.Therefore, MIMO technology will be one of the most important communication technologies in the future high speed mobile communication systems, and will play a unique advantage.In MIMO system, if the received antenna signal is not correlated, it can improve the anti-fading performance of the system, and can increase the system capacity by increasing the number of antennas, which can greatly improve the spectrum efficiency.However, because the interval between antennas can not be infinite, the received signals on each path are bound to have certain correlation.Therefore, in order to study the performance of MIMO and evaluate the performance of the system, it is necessary to study the characteristics of MIMO channel and establish a channel model suitable for the corresponding scenarios.Firstly, this paper introduces the research results of broadband wireless channel model and the problems to be solved.The characteristics of wireless fading channel, large scale fading, small scale fading and its envelope are analyzed.The small scale fading in MIMO channel is emphasized.Secondly, the basic theoretical knowledge of wireless channel modeling is introduced, including the classification of the key parameters of wireless channel modeling, the typical MIMO spatial channel model and the spatial correlation of MIMO channel.The correlation of MIMO channel is analyzed from two aspects of correlation matrix and correlation coefficient. Gao Si distribution, uniform distribution and Laplace distribution are considered as three possible angular power spectrum distributions of received signals.The calculation formula of channel spatial correlation coefficient is given in detail, and the simulation is carried out.The results show that the main factors affecting the antenna are: antenna spacing, arrival angle, Angle of Arrivala, AODO, Angle of Departure, angle spread AS, Angular spread) and angle power spectrum pass, Power Azimuth spectrum, etc. The results show that the correlation factors between antennas are: antenna spacing, AOAA, Angle of Arrivala, AODO, Angle of Departure, angle spreading ASS, Angular spread) and so on.Finally, the parameters of the channel model are described in detail, and the implementation process of the TGn MIMO channel is described in detail, and the detailed simulation idea and simulation flow of the channel model are given. The characteristics of the channel model such as time-domain response, cumulative distribution function diagram are given.Power delay spectrum, Doppler shift and correlation are analyzed and verified.It shows the rationality of the channel model and accords with the actual propagation environment of WLAN.The channel module is added to the system for overall simulation, and the PER performance under different antenna configurations and different channel models is compared, and some reference conclusions are obtained. Finally, the channel modeling based on the above model in high-speed environment is considered.The channel characteristics are simulated and the rationality of the model is verified.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3

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