基于波形分集的UWB信号收发系统研究

在Haar小波合成窄脉冲技术的基础上,首次提出了超宽带信号的Haar波形分集(WD) 收发技术。不同阶的Haar小波合成的窄脉冲,通过发射系统发射到接收系统,接收机对不同阶的Haar 小波进行检测,该相关检测技术能够非常精确地提取所发射UWB窄脉冲中的各阶Haar小波。由于 Haar小波易于数字化实现,对实际应用有很重要的意义。     

高斯信道超宽带通信信号设计

超宽带无线通信是利用频带非常宽、中心频率相对较低的信号进行信息传输。由于它可以用较低的发射功率进行高速传输，因而成为室内短距离无线通信的最佳选择。通过分析信号的特性及其在高斯信道中传播的特点，对Euclidean矩和比特误码率进行具体的仿真分析，最后给出了二维超宽带通信信号的设计公式。     

基于UWB的室内定位平台设计及应用

为了设计一套高精度、高实时性、操作简单的室内定位系统,该系统采用DW1000芯片设计制作了UWB定位硬件板;以node.js为基础,使用htm15、css3和js搭建了web界面;使用socket.io技术实现了前后端的双向实时通信。为了保证定位精度,采用双边双向测距方法来测量距离,用双曲线模型定位算法来解析定位结果。对整个定位平台进行了实验测试,测试结果表明该平台运行稳定,web界面能实时清晰地显示标签位置,并且标签的定点精度在10 cm左右,动点精度在20 cm左右。     

室内可见光通信系统设计分析

可见光通信技术是一类新型的技术,具有节约能源的特点,可以满足当前社会的低碳需求,故此该技术的推广意义非凡。当前,很多人开始关注室内可见光的技术应用,我国的相关专业人员也开始将研究重点转移到该项研究上,目的是发挥室内可见光的最大功能。本文细致的阐述了通信技术关键性手段,并探究室内可见光的关键技术应用要点,用以推进我国的技术发展,创新我国的通信技术。     

UWB室内外信道模型分析

对UWB信号的室内外信道模型进行分析及综合讨论。基于Fresnel-Kirchoff刃型模型,对室外信道模型进行了PPM调制信号的多径信道分析;基于RICE统计模型及RAKE接收机,对室内信道模型采用了确定性信道统计模型进行分析;并基于ARMA模型,对室内信道模型采用了自回归信道模型方法分析。在理论分析的基础上给出了计算机仿真结果。     

满足FCC辐射掩模的UWB信号设计算法及性能分析

脉冲波形设计是超宽带无线通信技术研究中的重要内容。以满足联邦通信委员会(FCC)辐射掩模为前提,采用两次迭代的算法逐步对脉冲波形参数进行优化,设计了一种低复杂度、能够最大限度提高UWB系统的辐射功率的UWB信号。同时,研究了经过加性高斯白噪声(AWGN)信道,在跳时扩频脉位调制(TH-PPM)UWB系统中使用该窄脉冲的系统性能。仿真结果表明,该UWB通信系统比通常使用Manchester窄脉冲或Scholtz窄脉冲的UWB系统误码性能更优。这对于UWB系统的实际运用有很好的指导意义。     

差分混沌通信研究综述:信号设计与性能优化

作为一种低复杂度的非相干信息传输方案,差分混沌通信系统以其良好的抗多径衰落性能而受到广泛关注。近年来,研究者围绕着以差分混沌移位键控(DCSK)为代表的差分混沌通信开展了一系列富有成效的研究,逐渐发展了差分混沌通信的信号设计与性能优化方法。为此,该文从信号帧结构设计、正交多级信号设计、信号星座图设计和多载波信号设计4个层面详细综述了差分混沌通信信号设计的主要研究进展。此外,该文重点总结了面向差分混沌通信的噪声抑制辅助性能优化、索引调制辅助性能优化和混沌成形滤波辅助性能优化等方面的研究工作。     

高楼室内无线信号覆盖创新方案研究

随着我国经济的迅猛发展,城市建设的步伐逐步加快,很多栋高楼迅速被建起,人们在高楼中工作和生活的时间也逐渐变长,对高楼内的无线信号覆盖的要求也越来越高,保证高楼中人们的正常通信已经成为运营商无线信号覆盖的重要组成部分。由于高楼中墙壁对无线信号的遮挡等各种原因,室内用户手机信号比较弱,经常出现通信异常。本文通过新的无线信号覆盖解决方案,解决无线信号覆盖问题,满足高楼中室内用户的通信需求。     

UWB信号光纤传输性能分析

该文分析了超宽带(UWB)信号光纤传输的性能,分析对比了电UWBmonocycle和doublet信号经过光强度调制后光纤传输的性能,介绍了两种光生UWBmonocycle脉冲的方法,分析了这两种方法产生的信号经光纤传输后的时域波形与频谱。研究结果对实际的UWBover fiber系统应用具有指导意义。     

一种新的UWB通信脉冲设计

研究了基于FCC辐射遮蔽约束的超宽带无线通信系统超短脉冲波形设计方法.以具有不同形状因子和频谱搬移因子的高斯二阶微分脉冲为基函数,提出迭代组合和LMMSE（线性最小均方误差）组合的UWB（超宽带）脉冲设计方法.对采用迭代组合脉冲或高斯二阶微分脉冲的系统在高斯信道下的单链路误比特率、多址、多径等性能进行了仿真比较,验证了所提出的组合脉冲设计方法.     

Fluid coding and coexistence in ultra wide band networks

Time Hopping Ultra Wide Band (TH–UWB) commonly encodes the data symbols by shifting the position of the transmitted pulses by a quantity that is quantized over the inter-pulse interval range. In this paper, we relax the hypothesis of a discrete value for the time shift introduced by the TH code, by considering the possibility of generating real-valued codes that introduce time hopping in a “fluid” way. The effect on the power spectral density of generated signals is analyzed, and application of fluid coding to multiple access and to network coexistence is investigated by simulation. Portions of this work were presented at the 2005 2nd International Workshop Networking with Ultra Wide Band, Workshop on Ultra Wide Band for Sensor Networks [M.G. Di Benedetto, G. Giancola, D. Domenicali and P. Ingargiola “Fluid Coding in Time Hopping Ultra Wide Band Networks,” Proceedings of the IEEE 2nd International Workshop Networking with Ultra Wide Band—Ultra Wide Band for Sensor Networks, July 2005, Rome, Italy]. Daniele Domenicali took his Laurea degree in Telecommunications Engineering at the University of Rome La Sapienza in 2004. In November 2004 Domenicali wins the open competition for PhD scholarship in Information and Communication Engineering. He is teaching assistant for the course of “UWB Communication Systems” conducted by Professor Maria Gabriella Di Benedetto at the University of Rome La Sapienza. His research activity includes Pulse Shaping and the related modulation and coding techniques (Time Hopping Coding, PAM and PPM Modulation). Particular attention is paid to the effects produced in the Power Spectral Density, in order to find solutions capable of optimizing spectrum occupation while meeting the constraints imposed by emission masks. Daniele Domenicali is involved in the European Network of Excellence HYCON (Hybrid Control: Taming Heterogeneity and Complexity of Networked Embedded Systems). Guerino Giancola received the “Laurea” degree (magna cum laude) in Telecommunications Engineering, and the Ph.D. degree in Information and Communication Engineering from University of Rome La Sapienza, in 2001 and 2005, respectively. He is currently a research affiliate at the INFOCOM Department at University of Rome La Sapienza, where is actually holding the course of “Electrical Communications” for the degree on Electronic Engineering. His research interests include the analysis and modelling of Multi User Interference in Impulse Radio systems, and the design of Medium Access Control functions and protocols for UWB ad-hoc networks. Guerino Giancola recently co-authored with Prof. Maria-Gabriella Di Benedetto a book on Ultra Wide Band from radio to the network, titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall in June 2004. He is now involved in the European project “PULSERS – Pervasive Ultra wideband Low Spectral Energy Radio Systems” and in the European Network of Excellence “HYCON- Hybrid Control: Taming Heterogeneity and Complexity of Networked Embedded Systems”. Guerino Giancola is a member of the IEEE Communication Society. Maria-Gabriella Di Benedetto obtained her Ph.D. in Telecommunications in 1987 from the University of Rome La Sapienza, Italy. In 1991, she joined the Faculty of Engineering of University of Rome La Sapienza, where currently she is a Full Professor of Telecommunications at the Infocom Department. She has held visiting positions at the Massachusetts Institute of Technology, the University of California, Berkeley, and the University of Paris XI, France. In 1994, she received the Mac Kay Professorship award from the University of California, Berkeley. Her research interests include wireless communication systems and speech science. From 1995 to 2000, she directed four European projects for the design of UMTS. Since 2000, she has been active in fostering the development of Ultra Wide Band (UWB) radio communications in Europe. Within the 5th framework, she directed for the Infocom Dept. two European projects (whyless.com and UCAN) aimed at the design and implementation of UWB ad-hoc networks. Currently, within the 6th EU Framework, her “Networking with UWB” research group participates in the PULSERS Integrated Project which will integrate UWB research and development in Europe for the next years, and in the LIAISON Integrated Project as regards the application of UWB to location-based services. She also participates in the HYCON network of excellence. Dr. Di Benedetto is co-edited several Special Issues on UWB communications and networks for several Journals including IEEE JSAC, Journal of Communications and Networks, Mobile Networks and Applications, Eurasip. In 2004, Dr. Di Benedetto co-authored with G. Giancola the first published book on UWB for communications titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall. She recently completed the co-edition of two new books on UWB that will be published by 2005: UWB Communication Systems - A comprehensive overview, with T. Kaiser, D. Porcino, A. Molisch, and I. Oppermann, Hindawi Publishing Corporation, 2005, andUltra Wideband Wireless Communications with H. Arslan and Z.N. Chen, John Wiley & Sons, Inc., 2005.     

A compact CPW fed slot antenna for ultra wide band applications

A printed compact coplanar waveguide fed triangular slot antenna for ultra wide band (UWB) communication systems is presented. The antenna comprises of a triangular slot loaded ground plane with a T shaped strip radiator to enhance the bandwidth and radiation. This compact antenna has a dimension of 26 mm × 26 mm when printed on a substrate of dielectric constant 4.4 and thickness 1.6 mm. Design equations are implemented and validated for different substrates. The pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity and virtually steady group delay. The simulation and experiment reveal that the proposed antenna exhibits good impedance match, stable radiation patterns and constant gain and group delay over the entire operating band.     

Random projection method for ultra wideband signal acquisition

High-speed high-resolution analog-to-digital(A/D) conversion demanded by ultra wideband(UWB) signal processing is a very challenging problem.This paper proposes a parallel random projection method for UWB signal acquisition.The proposed method can achieve high sampling rate,high resolution and technical feasibility of hardware implementation.In the proposed method,an analog UWB signal is projected over a set of random sign functions.Then the low-rate high-resolution analog-to-digital convertors(ADCs) are us...     

端到端无线信道信号幅度和多普勒谱分布研究

利用理论和实验相结合的方法研究了室内宽带端到端(Device-to-Device,D2D)无线信道信号的幅度和多普勒频谱分布.结果表明:在不同的场景下,D2D信号幅度分布服从单瑞利、双瑞利和多瑞利的复合分布;在二维(Two-Dimension,2-D)和三维(Three-Dimension,3-D)散射环境下随电波到达角的分布不同,D2D信道多普勒频谱将遵循不同的分布规律.通过理论和实验结果的比较研究验证了本文结果的正确性.     

Design of low power CMOS ultra wide band low noise amplifier using noise canceling technique

This paper presents a design of a low power CMOS ultra-wideband (UWB) low noise amplifier (LNA) using a noise canceling technique with the TSMC 0.18 μm RF CMOS process. The proposed UWB LNA employs a current-reused structure to decrease the total power consumption instead of using a cascade stage. This structure spends the same DC current for operating two transistors simultaneously. The stagger-tuning technique, which was reported to achieve gain flatness in the required frequency, was adopted to have low and high resonance frequency points over the entire bandwidth from 3.1 to 10.6 GHz. The resonance points were set in 3 GHz and 10 GHz to provide enough gain flatness and return loss. In addition, the noise canceling technique was used to cancel the dominant noise source, which is generated by the first transistor. The simulation results show a flat gain (S₂₁>10 dB) with a good input impedance matching less than –10 dB and a minimum noise figure of 2.9 dB over the entire band. The proposed UWB LNA consumed 15.2 mW from a 1.8 V power supply.     

超宽带通信中一种新的伪混沌编码器及其解码方法

研究混沌编码技术在超宽带无线通信中的应用。提出一种新的伪混沌编码器结构,根据新的编码器结构,给出两种相应的解码方法,比较它们在AWGN信道中的解码性能,仿真结果表明本文方法的有效性。     

应用于宽频率范围的小卫星通信侦察信号处理方案

针对日益增强的小卫星平台搭载电子侦察载荷的需求,提出一种应用于宽频率范围的通信侦察信号处理方案,在一片集成度较低的FPGA中完成信号数字下变频、频谱分析、数据存储和传输等复杂功能。通过在FPGA中进行滤波器、存储器复用等办法,充分利用现有FPGA的资源,减少器件数量,实现了平台对载荷小型化、低功耗、功能全、效率高的要求。试验结果验证了该设计的实用性。     

Equaliser Performance for HIPERLAN in indoor channels

In order to accomplish practical deployment modelling for system performance evaluation and comparison for possible modulation and equalisation schemes to be used in HIPERLAN, a wide band tapped delay line (WTDL) channel model has been adopted by ETSI to characterise the multipath fading in the indoor radio environment. Based on this statistical channel model, and using Monte Carlo method, this paper evaluates the average probability of error for linear and decision feedback equaliser as a function of signal-to-noise ratio. It also evaluates the matched filter bound for this channel model. The results show the optimum performance levels achievable via the use of any equaliser.The work described in this paper was supported by the UK DTI/EPSRC LINK project: PC2011 High Throughput Radio Modem under EPSRC grant reference GR/K00318 in collaboration with Symbionics Networks limited.     

移动通信室内外空间几何信道模型的分析与比较

针对频率非选择性无线多径衰落信道,基于室外通信环境下的空心圆模型,提出了一种改进的适应于室内通信环境的空心圆模型。通过推导接收信号的空时联合分布以及边缘分布概率密度函数,分析和比较了两种空心圆几何信道模型的空时统计特性。通过空心圆的空心率以及收发机间距的信道参数变化,仿真结果阐明了空心圆模型在圆盘模型和圆环模型之间过渡的变化机理,以及不同无线通信环境下的信道信息。