移动通信信道建模与仿真研究

【作者】 喻火根；

【导师】 朱立东；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2009， 硕士

【摘要】 在通信系统设计过程中,需要通过仿真来分析系统的性能。移动通信信道的建模是通信系统仿真中必不可少的一环。故近年来不同无线传播环境下的信道建模成为了研究热点。本文分别对跳频瑞利衰落信道、非均匀散射环境下的瑞利衰落信道和移动台对移动台瑞利衰落信道的建模进行了深入的研究。全文的主要内容包括:首先给出了本文的研究意义;接着对本文研究的三类信道模型的现状进行了概述,指出了现有信道模型存在的一些问题;随后介绍了移动通信信道的一些基本概念及一些常用的信道建模方法,并对基于正弦和理论的建模方法作了详细的分析和讨论。针对跳频瑞利衰落信道,提出了一种新的基于正弦和理论的信道仿真模型。该仿真模型能在保持其它参数不变的条件下,通过仿真模型相位的跳变来模拟物理信道频率的跳变。并且该仿真模型考虑了不同载频信道间的频率相关性,通过仿真模型可方便的得出不同跳频频率间隔下信道的相关程度。由于该仿真模型中的所有参数都存在着闭合表达式,所以能对仿真模型的相关特性进行研究。通过理论分析,本文给出了该仿真模型的相关特性表达式。数值仿真表明,该仿真模型在低计算复杂度的条件下与参考模型在相关特性方面存在着极好的吻合。在很多无线传播环境中,信道中的散射体是非均匀分布的。故对非均匀散射环境下的信道进行建模成为了一个研究课题。因此,针对非均匀散射环境,本文提出了两种基于正弦和理论的平坦衰落瑞利信道仿真模型。在这两种仿真模型中,冯?米塞斯(von Mises)分布被用来描述非均匀散射环境下的信号到达角度。通过理论分析,给出了这两种仿真模型的相关特性。和现有仿真模型相比,这两种仿真模型与参考模型在相关特性上存在着更好的吻合。随着自组织网络系统、智能交通系统和中继通信系统等的发展,移动台对移动台的信道被广泛应用。因此,本文基于正弦和理论提出了三种移动台对移动台的平坦衰落瑞利信道仿真模型。这三种仿真模型都采用了“双环”散射模型。通过理论分析,给出了这三种仿真模型的相关特性。数值仿真表明,这三种仿真模型与参考模型在相关特性上存在着较好的吻合。更多还原

【Abstract】 In the process of communication system design, the performance of the communication system is analyzed through the simulation. The modeling of mobile radio channels is an indispensable part of communication system simulation. Therefore, the modeling of different radio propagation environments has become the research hotspot. This dissertation deeply investigates on the modeling of three types of mobile radio channels: the modeling of frequency hopping Rayleigh fading channels, the modeling of frequency non-selective Rayleigh fading channels under non-isotropic scattering environments and the modeling of frequency non-selective mobile-to-mobile Rayleigh fading channels. The research includes the following topics:Firstly, the dissertation gives a brief introduction of the research significance. Secondly, the current states of three types of channel models are introduced. Moreover, the problems of these channel models are pointed out. At last, the dissertation gives some basic concepts of mobile communication channel. And some approaches to the modeling of mobile radio channels are introduced, especially the modeling approach based on sum-of-sinusoids analyzed in detail.For frequency hopping Rayleigh fading channels, a new simulation model based on sum of sinusoids is proposed. It is shown that a frequency hop in the physical channel model corresponds to phase hops in the simulation model, while maintaining all other parameters unchanged. Moreover, the simulation model takes the frequency correlation into account. Through the simulation model, we can know the correlation between hops. Due to the fact that closed-form expressions are given for all simulation parameters, so the correlation properties of the proposed simulation model can be studied. Through theoretical analysis, the dissertation gives the expressions of the correlation properties. Numerical simulation shows that a pretty good agreement between the correlation properties of the simulation model and those of the underlying reference model has been observed in low computation complexity.In many radio propagation environments, the distribution of the scatterers of the channel is nonuniform. The channel modeling of non-isotropic scattering environments is a research topic. Therefore, two simulation models of Rayleigh channels based on sum of sinusoids are proposed for frequency non-selective mobile fading channels under non-isotropic scattering environments. In both simulation models, the von Mises distribution was used to characterize angle-of-arrival. Through theoretical analysis, the dissertation gives the correlation properties of the two simulation models. Compared with the existing model, the correlation properties of the two simulation models show better agreement with those of the reference model.With the development of mobile ad hoc networks and dedicated short-range communication systems for intelligent highways, mobile-to-mobile Rayleigh fading channels are widely used. Therefore, we propose three new simulation models based on sum of sinusoids. All of the three simulation models use the“double ring”concept. Through theoretical analysis, the dissertation gives the correlation properties of the three simulation models. Numerical simulation shows that a good agreement between the correlation properties of the simulation models and those of the underlying reference model has been observed.更多还原