超宽带室内和室内—室外信道电波传播特性分析及建模

发布时间：2018-07-20 09:02

【摘要】：室内定位技术目前正迅速发展并且需求日益增加。超宽带(Ultra wide bandwidth,UWB)无线通信技术较其它短距无线通信技术在室内定位方面显现出抗干扰能力强、穿透性高、抗多径衰落能力强和厘米级定位精度等优势。超宽带信道特性的研究和信道模型的建立是定位系统设计和实现的基础和前提。本文采用频域测量方法和基于射线追踪和一致性几何绕射理论的仿真方法分析了室内及室内到室外场景的路径损耗和多径衰落特性并建立了数学模型。首先采用传统的统计分析方法进行频域测量,测量场景包括室内办公室视距环境及室内到走廊严重遮挡的非视距场景。由实测方案得到频率对应的路径损耗结果,采用最小二乘法及回归显著性校验方法拟合与检验,结果显示与距离相关的路径损耗满足对数正态分布,阴影衰落满足正态分布;子带频率的对数与路径损耗呈线性关系,频率衰减指数满足正态分布特性。针对多径特性,采用傅里叶反变换、加窗、CLEAN算法等对数据预处理得到信道冲激响应,根据室内与室内到走廊冲激响应的差异,室内功率延迟剖面(Power delay profile,PDP)采用分段指数模型来描述,各位置功率延迟剖面统计均值经分簇算法得到各簇首径及簇内各径信号到达时间位置和强度,并依据数值分析、数学统计和校验得到信道参数以及幅度衰落分布;室内到走廊环境的功率延迟剖面使用改进的分段指数规律来描述。通过构造等比例的室内办公室和室内到走廊的3D模型进行确定性仿真,对仿真结果采用与频域测量方法中相同的分析方法,分析结果显示路径损耗分布和多径衰落特征与实测方法一致,验证了确定性方法研究超宽带信道的合理性和适用性最后,根据实测和仿真方法中数据分析所采用的方法和结论,对路径损耗建立了与距离和频率均相关的数学解析模型;由多径衰落特征,对室内视距场景建立了双指数模型,对室内到走廊严重遮挡场景建立了分段指数模型。
[Abstract]:Indoor positioning technology is developing rapidly and the demand is increasing day by day. Compared with other short-range wireless communication technologies, Ultra wide bandwidth (UWB) has the advantages of strong anti-interference ability, high penetration, strong anti-multipath fading ability and centimeter-level positioning accuracy. The research of UWB channel characteristics and the establishment of channel model are the foundation and premise of the design and implementation of the positioning system. In this paper, the frequency domain measurement method and the simulation method based on ray tracing and consistent geometric diffraction theory are used to analyze the path loss and multipath fading characteristics of indoor and indoor scenes, and the mathematical model is established. Firstly, the traditional statistical analysis method is used to measure the frequency domain. The measurement scene includes the indoor office visual range environment and the non-visual range scene which is heavily occluded from the indoor to the corridor. The method of least square method and regression significance check method are used to fit and test the path loss corresponding to the frequency. The results show that the distance dependent path loss satisfies the logarithmic normal distribution and the shadow fading satisfies the normal distribution. The logarithm of the subband frequency is linearly related to the path loss, and the frequency attenuation exponent satisfies the normal distribution characteristic. In view of the multipath characteristics, the channel impulse response is obtained by using Fourier inverse transform and windowed clear algorithm. According to the difference between indoor and indoor to corridor impulse response, Power delay profile is described by a piecewise exponential model. The statistical mean of power delay profile of each position is obtained by clustering algorithm, and the time of arrival and intensity of the signals of each cluster head and each diameter within the cluster are obtained, and the numerical analysis is carried out. The channel parameters and amplitude fading distribution are obtained by mathematical statistics and calibration, and the power delay profile from indoor to corridor environment is described by improved piecewise exponential law. The deterministic simulation is carried out by constructing the equal proportion indoor office and indoor to corridor 3D model, and the simulation results are analyzed by the same analysis method as the frequency domain measurement method. The analysis results show that the path loss distribution and multipath fading characteristics are consistent with the measured method, which verifies the rationality and applicability of the deterministic method in the study of UWB channels. Finally, according to the methods and conclusions used in the data analysis of the measured and simulated methods, A mathematical analytical model related to distance and frequency is established for path loss, and a double exponential model for indoor visual range scene is established based on multipath fading characteristics, and a piecewise exponential model is established for serious occlusion scene from indoor to corridor.
【学位授予单位】：郑州轻工业学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925

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