Design Template and Measurements for Antenna Planning in an Indoor Radio Environment at 1800 MHz

Recently, the demand for an accurate design on the distribution of the antennas in shopping malls is growing rapidly. To provide a guaranteed coverage inside the shopping malls, mobile operators may have installed a lot more antennas than that is really needed. This over-engineering design has increased the installation and operation cost. Therefore, the need to have a relatively more accurate indoor design is the most requesting goal in the telecommunication industry. The purpose of this paper is to derive an indoor design template, which can facilitate mobile operators to evaluate efficiently the optimized number of antennas and their locations within a premises. A tunnel propagation model is used to represent the propagation loss in an indoor environment. Measurements are also taken to derive the losses of various media. Field tests are finally performed to verify the accuracy of the distribution of RF signal strength predicted by the design template.     

Measurements and Statistical Modeling of 900 MHz Radio Propagation Channels for Microcellular and Personal Communications in Tunnels

This paper reports the results of measurements of 900 MHz narrow-band radio wave propagation in four tunnels with pedestrians and vehicles. Analysis of the measured data files shows that the power distance factor ranges from 1.87 to 4.44. The power attenation rate with distance is insensitive to the location of the transmit antenna in the cross section of a tunnel, but the transmit antenna insertion loss is. The log-normal distribution fits slow variation of the received signals. The Racian distribution closely describes fast fading in the straight sections of tunnels. However, the Rayleigh distribution does not fit the fast fading in the curved sections of tunnels, as expected.     

Propagation at 2.0 GHz in an Enclosed Area Using a Coaxial Cable with Leaky Sections as the Transmitting Antenna

This paper presents the results of narrowband and wideband propagation measurements carried out at 2.0 GHz in a large enclosed area using a coaxial cable with leaky sections as the transmitting antenna. The narrowband measurements were devised to measure attenuation of radio signals and the wideband techniques to measure multipath impulse responses and their associated root mean square delay spread. Analysis of the narrowband data files shows that the received signal levels in the direction parallel to the cable generally decay and display peaks in front of leaky sections due to the specific attenuation and special structure of the cable. The received signal levels in the direction radial to the cable decrease slowly and the distance-power law exponent is found to be slightly larger than one. The slow and fast variations of the received signal levels are also examined. The results reveal that the slow variations do not follow the lognormal distribution, while the fast variations fit the Rayleigh distribution in both parallel and radial directions. Analysis of the wideband data files yields that the maximum value of the root mean square delay spread is 86.1 ns and the root mean square delay spread values are less than 55 ns 50% of the time. One therefore can conclude that the enclosed area channel excited by the coaxial cable with leaky sections has a broad coherent bandwidth and can support the data rate up to 2.3 Mb/s without equalization.     

Improving a Hybrid Method of Indoor Propagation Modeling for Wireless Communications Systems

1　IntroductionThewirelesscommunicationsystemshavebeendevelopedrapidlyintherecentyears.Ithasnotonlycalledresearchers’attentiontomodelingtechniquesinInternet[1 ] ,butalsomoreandmorepeopleen gagedin propagationmodelingforindoorwirelesscommunications.Theeffectivedesign ,assessmentandinstallationofaradionetworkinanindoorenvi ronmentrequireanaccuratecharacterizationoftheradiopropagationchannel.Raytracingisapopularmethodforthepredictionofradiochannelcharacter isticsofwirelesscommunicationsystems.R…     

Wideband Propagation Measurements and Channel Implications for Indoor Broadband Wireless Local Area Networks at the 60 GHz Band

This paper addresses some wideband propagation characteristics for Indoor Broadband Wireless LANs at the 60 GHz band. Important system design characteristics from measured results obtained from two wideband 60 GHz LOS radio links are presented. Measurements had been undertaken using the swept frequency channel sounding method. Analysis from the complex frequency responses in a worst-case scenario have yielded to a lower coherence bandwidth value of 5 MHz. Minimum and maximum B_0.9coherence bandwidths obtained with a directional horn transmit and an omnidirectional receive antenna is 1.10 MHz and 105.33 MHz respectively. It has been observed that the coherence bandwidth fluctuates significantly with the location of the receiver with respect to the base station. These results can be used for modelling and design of future Indoor BWLANs.     

无线移动信道的仿真

本文介绍了利用MATLAB来对无线移动信道进行仿真的方法.首先解释移动信号多径传播和因此造成的衰落的基本特性,然后重点对常见的瑞利衰落和莱斯衰落进行仿真.为了对衰落有个直观的表达,在仿真衰落的同时也给出了衰落幅度的分布或概率密度函数.     

辐射模缝隙馈源激励的2GHz无线电波在室内的传播

本文给出了用辐射模缝隙馈源作为发射天线时，2GHz窄带和宽带无线电波在室内传播特性的测量结果。对于窄带信号，主要测量了传播过程中的衰减，测量结果表明，沿缝隙馈源方向，接收信号电平按指数规律衰减，在垂直于电缆方向上，接收信号电平的衰减较慢，损耗指数较小：在平行和垂直于馈源方向上慢衰落基本服从正态分布，而快衰落分别服从Rayleigh和Rician分布。对于宽带信号，测量了多径脉冲相应，得到了均方根时延扩展及其概率分布。     

室内无线电波传播实验研究

基于对数距离损耗模型,实验研究了普通会议室这一典型室内环境的电波传播特性。通过对传播损耗的测量数据的分析,给出了普通会议室环境下的路径损耗因子和相应的阴影衰落标准差,为室内无线通信系统设计提供了依据。     

Wideband Propagation Indoor Environment Measurements and Modeling in

This paper presents the results of widebandmeasurements of an indoor wireless radio channel at 1.8GHz. Propagation measurements were carried out in anindoor environment at the Technical University of Athens with a network analyzer. From themeasured impulse response (IR) profiles collected, meanexcess delay tau and root mean square of delay spreadtau Statistical analysis of delay spread and amplitude fading has been performed. Comparison withsimulation results extracted from SIRCIM Simulatorpackage has also been made. have beenestimated.     

GSM900MHz频段传播模型的校正

介绍了无线电波传播模型的作用、CW测试原理及规划软件Planet中的General模型的校正,并分析了问题区域存在的原因。     

Experimental Evaluation of Space Diversity Schemes at a Base Station in a Microcellular Environment at 900 MHz and 1800 MHz

The aim of this paper is to evaluate experimentallythe performance of different space diversity schemesat the base station end in a semi-urban microcellularenvironment. The receiving antennas were separated inhorizontal, vertical or compound direction in order toprovide decorrelated signals. The superior receivedsignal was chosen based on the selection combiningcriterion. A measurement campaign was conducted atboth appropriate frequency bands (900 MHz and 1800 MHz) for mobiletelecommunications. Measurements wereperformed along the route containing bothline-of-sight (LOS) and non-line-of-sight (NLOS)paths. The measured data was analyzed and signalcross-correlations, signal mean levels of individualreceiving branches and diversity gains of differentreceiving antenna separations (horizontal, verticaland compound) were evaluated. According to themeasurements, low signal cross-correlations andreasonable diversity gain at the base station end canbe achieved even with 4 separation ofthe receiving antennas in any direction at both 900 MHz and 1800 MHz frequencybands. The obtained resultsalso showed that horizontal, vertical and compoundspace diversity gains are almost the same. Hence,spatially small and variable antenna configurationsfor space diversity reception can be applied at thewall installations in a microcellular environment.     

基于传播损耗模型的最大似然估计室内定位算法

基于对数正态分布的室内传播损耗模型,本文利用最大似然估计算法,通过迭代估计得到用户与各个接收机之间的距离和相应的传播损耗模型中的遮蔽因子,并由此估计得到室内用户的位置。仿真结果表明,本算法收敛速度快,并有较高估计精度。     

Modeling of 3D In—Building Propagation by Ray Tracing Technique

Ｍｏｄｅｌｉｎｇｏｆ３ＤＩｎ－ＢｕｉｌｄｉｎｇＰｒｏｐａｇａｔｉｏｎｂｙＲａｙＴｒａｃｉｎｇＴｅｃｈｎｉｑｕｅＧｏｎｇＫｅ；ＸｕＲｕｉ（ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１０００８４）Ａｂｓｔｒａｃｔ：Ｔｈｅｍｏｄｅｌｉｎｇｏｆｉｎ...     

关于海面无线传播模型的探讨

现有文献中一般都认为海面环境的无线传播模型近似于自由空间传播模型，但在实际测试中发现，自由空间模型预测值与实测值差别较大，不能很好地解释此类环境的信号传播。笔者根据多次海面覆盖测试的数据，分析并拟合出了新的海面传播模型。     

战术通信无线传播研究

首先简要描述了战术指挥系统通信组成,并对其中的主要通信手段性能和优缺点进行了概括。其次就战术通信站点选择涉及到的相关要素进行了分析,并对通信传输过程中的电波传输损耗做了重点介绍,最后以Egli电波传播模型为例,结合具体的参数,进行了给定条件下的VHF电台传输损耗预测计算。     

室内带金属家具环境的电波传播特性研究

射线跟踪方法是研究室内复杂环境电波传播特性的有效技术。基于改进的入射及反弹射线法和镜像法研究了室内有金属家具的电波传播特性,仿真结果与已知文献测量结果对比,一致性良好,证明了该方法在室内复杂环境预测电波传播特性的正确性和有效性。仿真结果表明：（1）视距传播（LOS）绕射对接收功率贡献很小,可以忽略;非视距范围内（NLOS）绕射贡献较大,不可忽略,三次反射对整个室内的接收功率影响都很小。（2）金属家具的存在导致了视距范围内接收功率的剧烈波动,非视距范围内的接收功率波动不明显。（3）有金属家具房间的均方根时延变化幅度大。（4）到达角在空房间中近似于均匀分布,加入金属家具后,在视距范围内波动剧烈。（5）受到达角的影响,多普勒频移变化情况与到达角分布一致。分析结果为室内有金属家具环境的无线通信系统设计提供了有效的理论依据。     

带漏泄段同轴电缆激励的2GHz无线电波在大型封闭区域内的传播

本文给出了在大型封闭区域,用带漏泄段的同轴电缆作为发射天线时,2GHz窄带和宽带无线电波传播特性的测量结果,对于窄带信号、主要测量了传播过程中的衰减,测量结果表明,在平行于电缆方向上,接收信号的电平比垂直于电缆方向的电平大;接收信号的快衰落服从瑞利分而,而慢衰落不服从正态分布。对于宽带信号,测量了多径脉冲响应,得到了均方根时延扩展及其概率分布。     

隧道中UHF窄带无线电波传播信道的特性

本文以在五个不同隧道中的实验数据为基础，分析了窄带ＵＨＦ无线电波在隧道中的传播特性，给出了表征空直隧道传播损耗的距离因子，并讨论了隧道中的行人、车辆及隧道弯曲度对传播特性的影响。研究表明，接收信号的慢衰落基本服从对数正态分布，快衰落在直遂道中满足Ｒｉｃｉａｎ分布，在弯曲隧道中Ｒａｙｌｅｉｇｈ分布并不能很好地模拟快衰落的分布。     

室内长廊环境中毫米波传播特性仿真和分析

基于入射及反弹射线法/镜像法对室内走廊环境的毫米波传播进行了仿真和分析,仿真结果与测量结果一致性良好,验证了该方法的正确性.同时分析了仿真中得到的接收功率、均方根时延扩展、波达方向、均方根角度扩展和多普勒频移等传播参数,为毫米波通信系统室内覆盖提供了依据.