隧道环境与陆地上移动通信有显著不同,需要对其无线信道特性进行研究.本文提出了一种改进的射线跟踪法,能够对隧道环境无线信道特性高效地仿真,降低了射线跟踪的计算复杂度,同时采用一种新的坐标系描述弯道的几何形状,便于对弯道部分进...隧道环境与陆地上移动通信有显著不同,需要对其无线信道特性进行研究.本文提出了一种改进的射线跟踪法,能够对隧道环境无线信道特性高效地仿真,降低了射线跟踪的计算复杂度,同时采用一种新的坐标系描述弯道的几何形状,便于对弯道部分进行射线跟踪.本文将路径损耗的仿真结果与北京地铁14号线的实测结果进行对比,对比表明：改进的射线跟踪法能够有效地预测路径损耗;直道中K因子在-8~25 d B范围内变化,且随着距离增大有减小的趋势.展开更多
In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determin...In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determined by the average delay profile and the Doppler spectra. The profile characteristics and their influences on channel behavior are also examined.展开更多
This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical...This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical models for simulating the characterizations of different environments. A core idea of the simulator is to construct a Rice distribution-based multipath fading module produced by a modified Gans Doppler power spectrum, and in combination with a Markov model to predict the time-dependent characteristics of packet in different radio circumstances. It can simply predict the packet performance of the future channel and evaluate the relations between the radio channel and the modulation schemes, error control protocols and channel coding. Simulation results demonstrate that it is a reliable and efficient method.展开更多
结合地理信息技术(Geographic Information Sciences,GIS)的计算机仿真,已经成为无线电传播信道分析的重要手段之一。仿真软件“移动无线电”(Radio Mobile)可以对指定地形下的无线电波传播过程进行数值模拟,直接识别并导入多种地形数据...结合地理信息技术(Geographic Information Sciences,GIS)的计算机仿真,已经成为无线电传播信道分析的重要手段之一。仿真软件“移动无线电”(Radio Mobile)可以对指定地形下的无线电波传播过程进行数值模拟,直接识别并导入多种地形数据,但并不包括当今精度最高且国内广为流行的免费地形数据——先进星载热发射和反射辐射仪全球数字高程模型(Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model,ASTER GDEM),其精度可达30 m。因此,介绍一种如何将ASTER GDEM的数据读入Radio Mobile的处理方法。首先,利用GIS软件Global Mapper将ASTER GDEM压缩包数据转换为按照经纬度排列的DTED数据;其次,将DTED数据整理到以经度命名的文件夹内,每个文件按照纬度命名;最后,在Radio Mapper的地图属性设置中输入待仿真地域的经纬度,完成地形数据的导入。在此基础上,针对某一指定经纬度导入地形场景,利用Radio Mobile对电磁波的路径损耗做了初步的数值仿真。展开更多
文摘隧道环境与陆地上移动通信有显著不同,需要对其无线信道特性进行研究.本文提出了一种改进的射线跟踪法,能够对隧道环境无线信道特性高效地仿真,降低了射线跟踪的计算复杂度,同时采用一种新的坐标系描述弯道的几何形状,便于对弯道部分进行射线跟踪.本文将路径损耗的仿真结果与北京地铁14号线的实测结果进行对比,对比表明：改进的射线跟踪法能够有效地预测路径损耗;直道中K因子在-8~25 d B范围内变化,且随着距离增大有减小的趋势.
文摘In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determined by the average delay profile and the Doppler spectra. The profile characteristics and their influences on channel behavior are also examined.
基金Supported by the National Natural Science Foundation of China (40474055)
文摘This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical models for simulating the characterizations of different environments. A core idea of the simulator is to construct a Rice distribution-based multipath fading module produced by a modified Gans Doppler power spectrum, and in combination with a Markov model to predict the time-dependent characteristics of packet in different radio circumstances. It can simply predict the packet performance of the future channel and evaluate the relations between the radio channel and the modulation schemes, error control protocols and channel coding. Simulation results demonstrate that it is a reliable and efficient method.
