Wideband Channel Sounder With Measurements and Model for the 60 GHz Indoor Radio Channel

In this paper, a wideband channel sounder and measurement results for the short range indoor 60 GHz channel are presented. The channel sounder is based on a 1 gigasamples/s dual channel arbitrary waveform generator and A/D converter/software demodulator, which synthesize and detect a baseband PN sequence with 500 MHz bandwidth. A heterodyne transmitter and receiver translate the baseband PN sequence to and from the 60 GHz band. Ten channel measurements taken across the 59 GHz to 64 GHz range are concatenated to provide a continuous channel measurement covering 5 GHz of bandwidth, resulting in 0.2 ns time domain channel impulse response resolution. The dynamic range and maximum sensitivity performance of the channel sounder are discussed in detail. Comparisons of results with a vector network analyzer based system are shown to verify the accuracy of the sounder. In an extensive measurement campaign with vertically polarized omnidirectional antennas, several different rooms (offices, labs, conference rooms and others) in four different buildings have been investigated. Over 700 channel measurements are the basis for a comprehensive characterization of the short range 60 GHz indoor radio channel with omnidirectional antennas. Finally, a simple stochastic static multipath channel model is derived from the measurement results.     

Characterization of the Indoor/Outdoor to Indoor MIMO Radio Channel at 2.140 GHz

In this paper the radio channel characteristics of the 8 × 4 MIMO system consisting of a base station and a small terminal equipped with multiple antennas for indoor-indoor and outdoor-indoor scenarios are presented. We study the large-scale variation and small-scale characteristics of the measured channel coefficients. Although the mean received power is very much dependent on the measured location, the channel capacity seems to be unchanged when the receiver's location is altered. The data collected from different scenarios (e.g. measurement locations, antenna setting) were used to investigate the advantage of having the knowledge of the channel at both ends of the transmission link. It is shown that using the water filling algorithm there is indeed an increase in the channel capacity. At low SNR, the benefit of knowing the channel at both link ends observed in the measurement data is much higher than which can be obtained in the channel matrix with usual assumption on identical independently distributed components. Using the small-scale and large-scale information in the formulation of the channel capacity we show that in our measurement, the variation of the mean received power has a greater influence on the change of the overall system performance than the change in the environmental multipath scattering property.     

60GHz 室内信道下一种快速天线选择算法

传统的基于信道容量最大化准则的天线选择算法虽然使信道容量达到了最大化,但是计算复杂度很高。针对计算复杂度高的问题, 提出了一种基于Doolittle-QR 分解的低复杂度天线选择算法。该算法基于Doolittle-QR 分解,可以快速选择出使系统容量最大化的天线。与传统的天线选择算法相比,该算法的计算复杂度不仅有效地降低了, 而且容量性能相近。在60GHz 室内信道下,仿真实验结果表明, 该算法具有良好的容量性能,优于随机天线选择算法,接近最优天线选择算法。     

A Dynamic Model of the Indoor Channel

This paper proposes a new approach to modeling the radio channel experienced by transceivers moving in an indoor environment. For modeling the time-varying impulse response (IR) a randomly time-varyingpower-delay profile (PDP) is used, which enables the use of PDPs specific to local environments while widely different environments still can be included in the model. The PDPs are expanded in terms of so-called cluster functions modeling ray scattering on major physical objects in the environment. By using random weighting of the cluster functions, transceiver movements in some imaginary environment is modeled. In addition to the new model, the paper also presents results obtained from measurements of the indoor channel. A good agreement is found between measurement and model data, and thus the concepts applied in the new model seem to be useful in practice.     

Polarization Effects for Indoor Wireless Communications at 60 GHz

This letter studies the performance of indoor wireless communication systems operating at 60 GHz with different polarization schemes. Circular polarization is known to reduce multipath effects in line-of-sight (LOS) environments in the 60 GHz band. We propose a modified channel model based on the IEEE 802.15.3c channel model to incorporate the polarization effects. We then use this model to evaluate the error performance of a wireless communication system that uses circular polarization. The results are compared with linear polarization for LOS environments.     

A Geometric-Statistic Channel Model for THz Indoor Communications

The eventual practical deployment of a terahertz (THz) wireless communication system requires a proper channel model. By considering the unique characteristics of THz propagation, this paper proposes a geometric-statistic channel model for system-level simulation. This work also provides an evaluation methodology for investigating the system performance. Numerical results reveal that the proposed channel model is not only suitable to describe the physical characteristics of the THz channel, but also to investigate system-level performance.     

60 GHz与300 GHz频段航天器舱内通信信道特性

太赫兹(THz)技术有望在航天器舱体轻质化和舱内高容量传输需求方面发挥重要作用.本文构建了典型航天器舱内毫米波60 GHz与太赫兹300 GHz频段信道三维仿真模型,基于射线追踪法获取了两种典型发射机部署位置下的无线信道特性,提取并分析了路径损耗指数、阴影衰落因子、莱斯K因子、均方根时延扩展和角度扩展等关键信道参数,研究了发射机的部署位置对特定频段舱内信道的影响.结果表明：相同环境下,频率越高、路径损耗与莱斯K因子越大而时延扩展越小;相同频率下,发射机部署于舱内角落的信道特性优于部署于舱内上壁中央.本文所研究的无线信道特性将为未来复杂舱内环境下的太赫兹通信系统设计和部署提供启示.     

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.     

基于无线信道指纹的室内位置感应系统分析(英文)

This paper reviews and analyses various simplified-RFID (Radio Frequency Identification) indoor location systems, and proposes an improved implementation based on the propagation channel "fingerprinting" principle. The focus of the design aims to provide accurate location estimation, while minimising infrastructural requirements. The proposed approach is based on the LANDMARC (Indoor Location Sensing Using Active RFID) with Virtual Reference tags (VIRE) and implemented with dynamic linear interpolation and ...     

Statistical Inter-Floor Radio Channel Model

Wireless Personal Communications - Statistical inter-floor radio channel model is proposed, based on extension of the existing single-floor Saleh–Valenzuela model. Instead of cluster of rays,...     

A Markov Model for Indoor Ultra-wideband Channel with People Shadowing

For an indoor ultra-wideband (UWB) communication system, the line-of-sight (LOS) between the transmitter and receiver may be frequently blocked by moving people. Blocking of LOS may significantly affect the quality of service of on-going UWB communications. Based on the Angular Power Spectrum Density and the human blocking models, we build a packet-level UWB channel model considering the shadowing processes based on a Finite-state Markov Chain. The model is simple enough to be incorporated into existing network simulators like NS-2 and it can be used to facilitate protocol design and quality of service analysis for UWB based wireless personal area networks.     

无线信道的可视化建模和仿真

无线信道是移动通信的传输媒体,研究其特性并建立一个与实际传输环境相符合的无线信道仿真模型都有着十分重要的现实意义。本文首先提出无线多径衰落信道的广义平稳非相关散射（Wide-Sense Stationary Un-correlated Scattering,简称WSSUS）假设,并在该假设下对该信道的计算机仿真模型进行了研究;最后选择MATLAB6.X的仿真工具箱SIMULINK作为图形建模的支持环境,对多径无线信道的冲激响应进行可视化建模和仿真。     

超宽带室内信道仿真分析

对超宽带通信室内修正S-V信道模型的进行仿真,在分析S-V信道模型的参数特点的基础上,探讨修正S-V信道模型的数学模型的建立方法,在CM4的非视距(NLOS)信道环境下,用Matlab进行仿真实验,结果表明修正S-V信道模型更接近实际,比S-V信道模型具有更好的信道冲激响应特性,能够更好地应用于超宽带通信系统性能的信道传输特性研究。     

A BER-Based Partitioned Model for a 2.4GHz Vehicle-to-Vehicle Expressway Channel

Statistical channel models based on BER performance are presented for a frequency- and time-selective vehicle-to-vehicle wireless communications link in an expressway environment in Atlanta, Georgia, where both vehicles traveled in the same direction. The models are developed from measurements taken using the direct sequence spread spectrum (DSSS) technique at 2.45GHz. A collection of tapped delay line models, referred to as a “partitioned” model in the paper, is developed to attempt to capture the extremes of BER performance of the recorded channel. Overall and partition models are compared to the recorded channel in terms of the BER statistics obtained when the channels are inserted in a dedicated short range radio (DSRC) standard simulation system. The quality of the match between synthesized and recorded channel BER statistics is analyzed with respect to type of modulation (fixed or adaptive), the frame length, and the length of the interval over which the BER was calculated. Guillermo Acosta was born in Mexico City, Mexico, in 1962. He is a Ph.D. Candidate and a graduate research assistant in the School of Electrical and Computer Engineering at the Georgia Institute of Technology, in Atlanta, Georgia. He obtained his Bachelor of Engineering with Honors and Master of Engineering, both in Electrical Engineering, from Stevens Institute of Technology, Hoboken, New Jersey, in 1985 and 1987, respectively. He also obtained a Master of Business Administration with Honors from the Instituto Tecnologico Autonomo de Mexico (ITAM), Mexico City, Mexico, in 1996. Mr. Acosta has held technical and managerial positions in the recording, radio, and TV industries and in the Communications Ministry of Mexico. He has been an adjunct instructor in Electrical Engineering in the Instituto Tecnologico y Estudios Superiores de Monterrey Campus Estado de Mexico (ITESM-CEM) and the Universidad Iberoamericana. He is member of the IEEE, INCE, Tau Beta Pi, and Eta Kappa Nu. Mary Ann Ingram received the B.E.E. and Ph.D. degrees from the Georgia Institute of Technology, in Atlanta, Georgia, in 1983 and 1989, respectively. From 1983 to 1986, she was a Research Engineer with the Georgia Tech Research Institute in Atlanta, performing studies on radar electronic countermeasure (ECM) systems. In 1986, she became a graduate research assistant with the School of Electrical and Computer Engineering at the Georgia Institute of Technology, where in 1989, she became a Faculty Member and is currently Professor. Her early research areas were optical communications and radar systems. In 1997, she established the Smart Antenna Research Laboratory (SARL), which emphasizes the application of multiple antennas to wireless communication systems. The SARL performs system analysis and design, channel measurement, and prototyping, relating to a wide range of wireless applications, including wireless local area network (WLAN) and satellite communications, with focus on the lower layers of communication networks. Dr. Ingram is a Senior Member of the IEEE.     

A Multipath Fading Channel Model for Terrestrial Digital Radio Systems

The frequency transfer function of a multipath fading channel is examined in terms of its effects on digital radio signals. The transfer function is expanded into a power series about the channel center frequency and the coefficients are related to the multipath structure. It is then shown that, in the channelized common carrier bands below 15 GHz, the first two (complex) terms of the power series are usually sufficient for characterizing multipath effects. This demonstration is based on a mean-square error-of-fit measure which is applied to the multipath fading response and evaluated under some worst-case assumptions.     

A Fully Integrated 60GHz Four Channel CMOS Receiver with 7GHz Ultra-Wide Bandwidth for IEEE 802.11ad Standard

In this paper, a fully integrated CMOS receiver frontend for high-speed short range wireless applications centering at 60GHz millimeter wave （mmW） band is designed and implemented in 90nm CMOS technology. The 60GHz receiver is designed based on the super-heterodyne architecture consisting of a low noise amplifier （LNA） with inter-stage peaking technique, a single- balanced RF mixer, an IF amplifier, and a double-balanced I/Q down-conversion IF mixer. The proposed 60GHz receiver frontend derives from the sliding-IF structure and is designed with 7GHz ultra-wide bandwidth around 60GHz, supporting four 2.16GHz receiving channels from IEEE 802.1lad standard for next generation high speed Wi- Fi applications. Measured results show that the entire receiver achieves a peak gain of 12dB and an input 1-dB compression point of -14.SdBm, with a noise figure of lower than 7dB, while consumes a total DC current of only 60mA from a 1.2V voltage supply.     

6.0-6.4GHz室内MIMO无线信道测量与传播特性分析

工作在6GHz以上高频段的多输入多输出(Multi-Input-Multi-Output,MIMO)无线通信系统是下一代无线移动通信的有力竞争方案.目前,对制约无线系统性能的高频段空时无线信道特性研究仍较少见.针对这一现状,采用基于网络分析仪的信道测量平台对典型办公环境下6.0-6.4GHz MIMO无线信道特性进行测量和分析.为了明确高频段为系统设计带来的新问题,将测量得到的高频段MIMO信道特性参数与低频段对比.对比结果表明,6.2GHz频段与2.45GHz频段MIMO信道传播特性存在较大差异.在对6.0-6.4GHz室内覆盖MIMO无线通信系统进行设计和评估时,需要基于6.0-6.4GHz频段无线信道传播的新特性对系统的关键技术和方案进行调整.     

超宽带室内参考信道模型的研究

通用且随机的超宽带室内信道模型对物理层标准评价、系统设计和性能分析起重要作用。本文首先介绍了超宽带室内信道的典型特征,然后在信道探测的基础上详细描述了超宽带室内参考信道模型,并结合具体超宽带室内环境对信道模型参数进行仿真,将仿真结果与探测信道统计特性进行比较,分析了信道模型结构对系统设计和性能分析的影响,指出超宽带室内参考信道模型的局限性,最后得出进一步研究超宽带室内信道模型的必要性。     

基于簇的块稀疏压缩感知的60GHz信道估计

基于压缩感知设计适用于60 GHz毫米波通信系统的信道估计方案,深入研究了正交匹配追踪(OMP)算法和正则正交匹配追踪(Regularized OMP)算法的60 GHz信道估计性能;在此基础上,充分发掘60 GHz无线多径信道所呈现出的分簇特性,提出一种新颖的基于簇分级的稀疏压缩感知重构算法。新算法在有效减少重构迭代次数的前提下,亦能显著降低信道估计误差。综合对比分析了基于簇分块稀疏压缩感知重构算法和现有压缩感知算法在60 GHz信道估计应用中的重构性能,仿真结果表明,压缩感知算法可有效应用于60 GHz系统信道估计,而新设计的基于簇分级的稀疏压缩感知算法则在估计精度和实现复杂度方面具更优越性能。