室内无线信道测量与信道建模研究

发布时间：2018-04-08 20:21

本文选题：室内　切入点：信道测量　出处：《西安电子科技大学》2014年硕士论文

【摘要】：随着智能终端与移动互联网的普及,人们在室内环境里的通信活动越来越频繁,对无线通信的要求越来越高。通过信道测量构建信道模型来获取信道特性,不仅可作为通信系统设计的参考基础,而且也是改善通信质量的有效途径之一。本文考虑两实验室间的环境,设计测量方案并研究离线参数提取算法及信道建模问题。本文首先解释无线电波传播机制,并研究信道模型的分类,具体包括路径损耗模型、阴影衰落模型和小尺度衰落模型,给出路径损耗模型的几种经验模型和抽头延迟线模型,着重介绍了相关时间色散参数和频率色散参数的理论公式以及物理意义。然后给出测量场景,测量系统由硬件平台USRP以及软件平台GNU Radio构成,而测量系统硬件系统实际采用了USRP N210母板、RFX400子板和RFX2400子板。发射端和接收端处理过程以流程图的形式进行描绘,信道各路径信息可由相关法得到,相关性的表现因伪随机序列类型不同而有所差别,并存在规律来判断相关性优劣,重点比较了M序列和CAZAC序列的相关性。利用CAZAC序列并以滑动相关法为理论基础设计信道测量方案,依托测量系统在不同测量参数下进行信道测量,并且标明测量项目;最后设计接收数据离线处理流程,包括信号帧起始位置确定算法、多径门限提取算法、连续信道冲激响应提取算法、信道延时功率谱提取算法、多普勒功率谱提取算法。将数据依照该离线处理流程进行加工得到信道冲激响应这一中间参量,有相关峰形式的连续信道冲激响应和离散形式的信道冲激响应两种形式,由信道冲激响应提取出针对不同测量参数组合下的信道延时功率谱、最强径多普勒功率谱等参数,考究测量参数的不同对于以上信道参数的影响,最终采用统计的方法总结各条路径时延以及对应幅度的分布规律,构建适合两实验室间具有一定参考意义的抽头延迟线模型,并与理论分析模型具体参数进行对比。
[Abstract]:With the popularity of intelligent terminals and mobile Internet, communication activities in indoor environment become more and more frequent, and the requirement of wireless communication becomes higher and higher.Constructing channel model by channel measurement can not only be used as a reference for the design of communication system, but also an effective way to improve communication quality.In this paper, we consider the environment between the two laboratories, design the measurement scheme and study the off-line parameter extraction algorithm and channel modeling.This paper first explains the mechanism of radio wave propagation, and studies the classification of channel models, including path loss model, shadow fading model and small-scale fading model, and gives several empirical models and tap delay line models of path loss model.The theoretical formulas and physical significance of the related time dispersion parameters and frequency dispersion parameters are emphatically introduced.The measurement system is composed of hardware platform USRP and software platform GNU Radio. The hardware system of the measurement system uses USRP N210 motherboard RFX400 and RFX2400 subboard.The processing process of the transmitter and receiver is described in the form of flowchart. The channel path information can be obtained by correlation method. The performance of correlation varies with the type of pseudorandom sequence, and there are rules to judge the correlation.The correlation between M sequence and CAZAC sequence is emphasized.The channel measurement scheme is designed based on the CAZAC sequence and the sliding correlation method. The channel measurement is carried out under different measurement parameters based on the measurement system, and the measurement items are marked. Finally, the off-line processing flow of the received data is designed.It includes signal frame starting position determination algorithm, multipath threshold extraction algorithm, continuous channel impulse response extraction algorithm, channel delay power spectrum extraction algorithm, Doppler power spectrum extraction algorithm.The data are processed according to the off-line processing flow to obtain the intermediate parameter of channel impulse response, continuous channel impulse response in the form of correlation peak and channel impulse response in discrete form.The channel delay power spectrum and the strongest path Doppler power spectrum are extracted from the channel impulse response. The influence of different measurement parameters on the above channel parameters is studied.Finally, the statistical method is used to summarize the distribution law of each path delay and corresponding amplitude, and a tap delay line model suitable for reference between the two laboratories is constructed, and the specific parameters of the model are compared with the theoretical analysis model.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92

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