Tutorials to be presented at VTC 2007 Spring
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T1: Advances in Multiuser MIMO Systems
Presenter: Li-Chun Wang and Tomoaki Ohtsuki
Time: AM
Room:
Abstract
Multiple-input multiple-output (MIMO) antenna techniques have been the subject of great interest over the past decade and have been adopted in the emerging wireless systems. Recently, personalized broadcast becomes an interesting and important application for MIMO technologies, which aims to serve multiple users concurrently with personalized data for each individual user. Interestingly, the potential gains of MIMO antenna techniques in this point-to-multipoint environment can be even larger than for the point-to-point system. The goal of this tutorial is to provide attendees with an understanding of benefit and tradeoff of implementing MIMO personalized broadcast systems. The key enabling techniques for MIMO personalized broadcast systems, including dirty paper coding, scheduling, transmit beamforming, receive beamforming, and feedback mechanisms will be investigated from the system and network perspective in this tutorial
Tutorial Objectives
MIMO personalized multicast systems aims to serve multiple users concurrently with personalized data for each individual user. However, to exploit the potential gains of MIMO antenna techniques in this point-to-multipoint environment, many proposed enabling techniques are needed to be investigated from a system and network aspect. This is also the major goal of this tutorial.
In this tutorial, we will discuss several key enabling techniques for MIMO personalized broadcast systems. We will investigate dirty paper coding, scheduling, transmit beamforming, receive beamforming, and feedback mechanisms for MIMO personalized broadcast system from the system and network perspective.
The participants are expected to learn the benefit and tradeoff of different enabling techniques to implemen MIMO personalized broadcast systems, including dirty paper coding, scheduling, transmit beamforming, receive beamforming, feedback mechanisms, fairness, and power allocation issues. We also will highlight the future promising multiuser MIMO systems, such as multi-user MIMO-OFDM and peer-to-peer MIMO ad hoc networks.
Tutorial Outline
- 1.Background on MIMO antenna techniques (0.25 hr)
- 2.Optimal Dirty Paper Coding (0.25)
- 3.Spatial Multiplexing in point-to-multipoint systems by transmit beamforming (0.5hr)
- 3.1 Opportunistic beamforming
- 3.2 Random beamforming
- 3.3 Zero-Forcing beamforming
- 4. Spatial Multiplexing in point-to-multipoint systems by receive beamforming and scheduling (0.5hr)
- 4.1 Proportional fair scheduling
- 4.2 Max/Max scheduling
- 4.3 Max/Min scheduling
- 5. Feedback mechanism, fairness, and power allocation issues (0.75 hr)
- 6. Mulituser MIMO-OFDM (0.5 hr)
- 7. Peer-to-peer MIMO ad hoc networks (0.25 hr)
- 8. Conclusion (0.25 hr)
Primary Audience
This course will be of interest to graduate students in a communications option of electrical engineering and who are interested in both the physical and higher layers. The course will also be of interest to engineers who are working with future standaard of wireless communications systems.
Novelty
In addition to discuss several key enabling techniques for MIMO personalized broadcast systems, we also introduce many new concepts and techniques in MIMO system. First, we will introduce the "soft coverage" concept in MIMO systems -- to utilize limited-feedback scheduling techniques to enhance the coverage of MIMO systems without increasing transmission power. Second, we will explain how scheduling can simplify the desing of MIMO transceiver. In particular, we will show the zero-forcing MIMO transceiver, which has noise enhancement issue originally, can indeed approach the performance of the optimal MIMO receiver with multiuser scheduling.
Biography
Dr. Li-Chun Wang received the B.S. degree from National Chiao Tung University , Taiwan, R. O. C. in 1986, the M.S. degree from National Taiwan University in 1988, and the Ms. Sci. and Ph. D. degrees from the Georgia Institute of Technology , Atlanta, in 1995, and 1996, respectively, all in electrical engineering. From 1990 to 1992, he was with the Telecommunications Laboratories of the Ministry of Transportations and Communications in Taiwan (currently the Telecom Labs of Chunghwa Telecom Co.). In 1995, he was affiliated with Bell Northern Research of Northern Telecom, Inc., Richardson, TX. From 1996 to 2000, he was with AT&T Laboratories, where he was a Senior Technical Staff Member in the Wireless Communications Research Department. Since August 2000, he has joined the Department of Communication Engineering of National Chiao Tung University in Taiwan as an Associate Professor and has been promoted to a full professor since August 2005. His current research interests are in the areas of cellular architectures, radio network resource management, cross-layer optimization, and cooperation wireless communications networks. Dr. Wang was a co-recipient (with Gordon L. Stuer and Chin-Tau Lea) of the 1997 IEEE Jack Neubauer Best Paper Award from the IEEE Vehicular Technology Society. He is an associate editor for the IEEE Transactions on Wireless Communications and holding three US patents.
Dr. Tomoaki Ohtsuki received the B.E., M.E., and Ph. D. degrees in Electrical Engineering from Keio University, Yokohama, Japan in 1990, 1992, and 1994, respectively. From 1994 to 1995 he was a Post Doctoral Fellow and a Visiting Researcher in Electrical Engineering at Keio University. From 1993 to 1995 he was a Special Researcher of Fellowships of the Japan Society for the Promotion of Science for Japanese Junior Scientists. From 1995 to 2005 he was with Tokyo University of Science. From 1998 to 1999 he was with the department of electrical engineering and computer sciences, University of California, Berkeley. He is now an Associate Professor at Keio University. He is engaged in research on wireless communications, optical communications, signal processing, and information theory. Dr. Ohtsuki is a recipient of the 1997 Inoue Research Award for Young Scientist, the 1997 Hiroshi Ando Memorial Young Engineering Award, Ericsson Young Scientist Award 2000, 2002 Funai Information and Science Award for Young Scientist, and IEEE the 1st Asia-Pacific Young Researcher Award 2001.
T2: RFID Systems
Presenter: Boon Sain Yeo, Wavex Technologies Pte Ltd
Time: AM
Room:
Abstract
Radio Frequency Identification (RFID) has been around for decades and has been generally regarded as a matured technology ready for market adoption and deployment. However, the adoption of RFID has not received the whelming response as the market and players have eagerly anticipated. What went wrong with this technology, despite its advantages over competing technologies? Indeed, RFID is a technology constrained by many differing environmental factors, of which need to be considered, before a successful system can be commissioned. The objective of the tutorial will unravel the technical, marketing and practical aspects underpinning RFID systems. The tutorial will also attempt to provide analysis of the differing technical specifications and applications governing RFID and Wireless Sensor Networks (WSN).
Tutorial Objectives
The objective of the tutorial will unravel and discuss the technica, marketing and practical aspects underpinning RFID systems. The tutorial will start off by providing extensive coverage on the different facets of RFID, with strong focus on the standards underlying LF, HF, UHF and active tag. It will then be followed with an in-depth focus and emphasis on HF system. It will also highlight the co-existance of different RFID technologies (LF, HF, UHF and active tags), in today's markets. It will provide a detailed understanding of the technical information unpinning the RFID systems, with special emphasis on HF given that this is the more provened and matured technology. The successful deployment of National Library Board of Singapore, a benchmark in world RFID library deployment, will be discussed and will be used as a case study to illustrate the economics and technical aspects of the potential of RFID systems. The tutorial will also attempt to provide some practical demonstrations on the design of HF circuitries and tuning of antenna, under different environmental influences. The tutorial will also provide differentiating factors between Wireless Sensor Networks (WSN) and RFID, both passive and active. It is worth noting that RFID has always been pushed for by the industry and WSN by the academia. However, there has been in increasing interest in WSN by the industry and RFID by the academia. The tutorial will conclude with the ongoing trend and to provide a visionary convergence approach between RFID and wireless sensor networks and ways and applications for its inter-working.
Tutorial Outline
- 1. Introduction
- 2. Overview of the various RFID Technologies
- 3. LF RFID System (ISO 18000-2)
- 4. HF RFID System (ISO 15693, 18000-3)
- 5. UHF RFID System (ISO 18000-6)
- 6. RFID and its Applications
- 7. Influences of environmental factors on RFID system (Some practical demonstrations and practical design concepts of HF RFID system will be shared and discussed)
- 8. A Successful Case study – RFID Library Management System
- 9. Market Adoption trend for RFID Systems
- 10. Discussions on Active RFID, Wireless Sensor and RFID – technological differences and co-existences
- 11. Future for RFID Systems
Primary Audience
Practicing engineers, research scientist, mid-level managers who are keen to understand the first hand practical info of deploying RFID system and those engineers and researchers involved in standardization activities.
Novelty
The tutorial is not about theory but true practical experience of the instructor, whom has participated actively in the roll out of 20+ libraries in Singapore and other RFID deployment activities, will be shared and discussed.
Biography
Boon Sain Yeo received the B.Eng and Ph.D. degrees in Electrical and Electronics Engineering from University of Glasgow and Imperial College of Science and Technology, respectively. . He has been with the Institute for Infocomm Research (I2R, formerly also known as Centre for Wireless Communications, NUS and Institute for Communications Research), an institute under Agency for Science, Technology and Research, since 1998. From 2004 – 2005, he was appointed as the laboratory head of Wireless Sensor Networks Laboratory in the Networking Department. Since 2005, he has been seconded to lead the technology division of Wavex Technologies, focusing on wireless development and RFID, and to setup Wavex Innovations, the R&D arm of Wavex Technologies, under a government initiative to help technologically upgrade the small medium enterprise in Singapore. He has participated actively and led a team of hardware engineers in the deployment of the 2nd generation RFID systems to the 22 Regional and Community Libraries for the National Library Board of Singapore (NLB). He was also the project manager for the RFID Smart-Shelf project, of which he initiated at I2R. The project was a collaboration between NLB, I2R and Wavex Technologies. He is also an adjunct Assistant Professor in NUS. His research interests are in technologies relating to wireless systems and network, and operational approaches to optimize telecommunication systems. He has been actively participating in numerous conferences, including, TPC co-chair for IEEE GLOBECOM 2004 Wireless symposium, TPC chair for IEEE GLOBECOM 2005 General symposium, TPC co-chair for IEEE GLOBECOM 2006 Wireless Symposium, General co-chair and Steering Committee Chair for ISWCS 2004, 2005, 2006 and 2007, General co-chair and Steering Committee Co-chair for ISWPC 2006 and 2007, General co-chair for VTC Spring 2008, TPC chair for WOCN 2005, Workshop chair for SensorWare 2006 and Organizing chair for IEEE MWCN 2003. He is also currently serving as a editorial board member for several reputable journals.
T3: Vehicular Communications Networks
Presenter: M. Nekovee ( BT Research), M-L Sim (Multimedia University) Y. F. Ko (University of Portsmouth)
Time: AM
Room:
Abstract
Vehicular communications networks (VCNs) are created by vehicles equipped with short and medium range wireless communication technology. They include vehicular ad-hoc networks (VANET), vehicle-to-vehicle and vehicle-to-infrastructure communications. VCNs enable a plethora of important applications and services, ranging from in-motion broadband wireless access, to Intelligent Transport Systems (ITS). Appropriately, there is a growing interest in these networks from governments, industry and the research community. Automobile manufacturers are currently prototyping vehicles equipped with Wi-Fi and governments have recently allocated spectrum for vehicular communications.
In this tutorial we explore the unique features and challenges that characterise these highly dynamic networks and explore their role in ITS and the provisioning of broadband wireless access to users on the road. We review state-of-the-art R&D in the development of system architectures, MAC protocols, routing and mobility management, modelling and performance analysis. We conclude by exploring future research directions. Where possible we will make use of demonstrations and case studies to illustrate the concepts and technologies presented.
Tutorial Objectives
This tutorial aims to provide participants with a combination of introductory and in-depth material, including demonstrations and case studies, which introduce the unique features and characteristics of high-speed wireless communications in vehicular setting. It explores key application areas and surveys the research challenges that they present across all communication layers. Subsequently, we aim to review state-of-the-art R&D (both our own and others) that attempts to address these challenges and explore open research questions and relevant emerging technologies, including dynamic spectrum access and cognitive radio.
Tutorial Outline
- 1. Introduction
- 2. Fundamentals
- 2.1 System Architectures
- 2.2 Deployment and timelines
- 3. Future application areas and requirements
- 3.1 In-motion broadband wireless access without 3G
- 3.2 Intelligent Transport Systems
- 4.Characteristics of VCNs
- 4.1 Vehicular traffic and movement patterns
- 4.2 Dynamic network topology
- 4.3 Wireless networking at speeds
- 5. Networking and wireless communication: challenges and proposed solutions
- 5.1 MAC protocols for VANET
- 5.2 Mobile handoff at speeds
- 5.3 Routing and information dissemination in intermittently connected VANET
- 5.4 Network architectures
- 5.5 Security and cyber-attacks
- 5.6 Performance modelling and simulations (including advanced vehicular mobility models)
- 5.7 Pricing models
- 6. Emerging technologies for VCN
- 6.1 Mobile WiMAX and mesh networks
- 6.2 Dynamic spectrum access and cognitive radios
- 7. Conclusions and perspectives
Primary Audience
This tutorial is for anyone who wishes to gain an understanding of the underlying principles, future applications and research directions in vehicular communications networks. The first part of the tutorial is suitable as an introductory crash-course for those looking for an initial exposure to the field. The second part will critically examine state-of-the-art in research and development for those looking for an in-depth understanding of vehicular communications networks.
Novelty
The field of vehicular communications networks has been gaining considerable momentum in the last few years. This is the first tutorial that provides a comprehensive study of this fast moving field and its novel applications. The unique requirements of inter-vehicular applications and the unique features of the vehicular network mean that new networking solutions are required for VCNs across all layers of communications, putting this area at the cutting-edge of wireless communication technology.
Biography
Maziar Nekovee is a senior scientist at BT’s Mobility Research Centre in Ipswich, UK. His research interests include vehicular communications networks, theory and applications of complex networks and cognitive radio networks. Prior to joining BT he held research posts at Imperial College and Queen Mary College in London. He received his MSc. in Electrical Engineering (cum laude) from Delft University of Technology in the Netherlands and his PhD in theoretical and computational Physics from the University of Nijmegen, also in the Netherlands. Dr Nekovee is the author of over 50 papers in international journals and conferences. He is a guest co-editor of a special issue of ACM/Springer Journal on Mobile Networks and Applications (MONET) on Cognitive Radios, and a guest co-editor of a focus issue of the New Journal of Physics on complex networks. Dr Nekovee is the recipient of a Royal Society (UK’s Academy of Science) Industry Fellowship, and an Honorary Senior Research Fellow at the University College London.
Moh Lim Sim is a senior lecturer in the Faculty of Engineering, Multimedia University, Malaysia He was with BT from Sept 2004 to Sept 2005 as Technical Group Leader. He has served as consultant to a number of companies and government agencies in Malaysia. Currently, he helps OCE Sdn Bhd to develop and design its own wireless mesh routers. His research interests include broadband wireless access, Wi-Fi mesh, and wireless sensor network. Dr. Sim is the co-author of one book, one book-chapter, and more than 30 international journal/ conference articles.
Yin Fern Ko is currently working towards her PhD at the Department of Electronic and Computer engineering, University of Portsmouth. Before taking up her PhD studies, she was a researcher at BT’s Asian Research , where she was involved in Wi-Fi mesh product evaluation and testbeds, co-existence of Wi-Fi and WiMAX studies and the provisioning of broadband wireless access for users on the road using Wi-Fi mesh networks. She received her MEng Electronic and Communications engineering from University of Nottingham, Malaysia Campus.
T4: WiMAX / IEEE 802.16
Presenter: Loutfi Nuaymi, ENST Bretagne
Time: AM
Room:
Abstract
WiMAX Technology, based on IEEE 802.16 standard has a rich set of features. In order to have a high radio resource use efficiency for different types of services, IEEE 802.16 standard includes many procedures and functions. In this tutorial, we briefly describe the main aspects of WiMAX in order to provide a global picture of this highly promising technology.
The protocol layers of IEEE 802.16 and the main procedures are described. The differences between 802.16-2004 and 16e are highlighted. Network Entry, Radio resource management, Security, Antenna techniques (MIMO and AAS), handover and power-save modes are tackled. We end by some comparisons with other wireless systems (3G, WiFi) and a conclusion.
Tutorial Objectives
The objective of this half-day tutorial is to provide a clear and concise technical introduction to WiMAX/IEEE 802.16 Broadband Wireless Access (BWA).
The participants will have descriptions of the major procedures of IEEE 802.16 and the framework of WiMAX. Among others, WiMAX OFDM-based multiple access and related mechanisms such link adaptation and scheduling are explained.
Tutorial Outline
- Introduction
- the need for broadband wireless access
- WiMAX and IEEE 802.16
- Certification and products
- WiMAX topologies
- The protocol layers
- The physical layer, link adaptation, OFDM transmission technique
- OFDMA, the permutation modes: PUSC, FUSC and AMC
- Convergence Sublayer (CS)
- The MAC Layer
- MAC procedures
- MAC Frames
- MAC data transport and management messages
- The multiple access
- link adaptation
- bandwidth request and multimedia services association
- Network Entry
- Radio Resource Management
- AAS
- MIMO
- WiMAX Network Architecture
- Mobility, handover and power save modes
- Security
- Comparisons; Conclusion
Primary Audience
This tutorial can be of great interest to any person wishing to have a technical introduction about WiMAX, convering all its major topics. Many research fields are highlighted.
Novelty
WiMAX is a very powerful but also sometimes complicated technology. This technical introduction covers the framework and all the major procedures of WiMAX/IEEE 802.16
Biography
Loutfi Nuaymi is Associate Professor at ENST Bretagne, located in Brest and Rennes, France. His fields of interest are radio resource management and planification in wireless networks: UMTS, WiFi and WiMAX. He got his PhD in Telecommunication from ENST, Paris, France in 2001. He is the author of "WiMAX", published at Wiley (January 2007) and many papers, conference contributions and book chapters. He takes part in many French national research projects.
T5: Adaptive MIMO Techniques and Performance
Presenter: I.B. Collings, R.W. Heath Jr.
Time: PM
Room:
Abstract
Multiple-input multiple-output (MIMO) antenna systems have recently attracted considerable attention as they offer substantial capacity and performance improvements over single antenna systems without requiring additional power or bandwidth. The initial MIMO research focussed on idealized uncorrelated scattering environments, and spawned an explosion of interest in the area. This tutorial will focus on new adaptive approaches to MIMO, for practical correlated channels. It will provide both analysis techniques and practical design studies.
Tutorial Objectives
This tutorial will present an introduction to general MIMO systems, with a particular focus on practical correlated transmission environments. We will discuss a number of low complexity transmission architectures suitable for practical coded MIMO implementations, including the IEEE802.11n and IEEE802.16 standards. The focus of the tutorial will be on examining the potential advantages that can be gained by adapting and switching between different coded MIMO transmission schemes, depending on the quality and correlation in the MIMO channel. A summary of the main analysis techniques will be presented, as well as simulation studies which examine the various system design tradeoffs.
Tutorial Outline
- Introduction
- General MIMO channel model
- Correlated MIMO channels and impact of array configuration
- Low Complexity Transmission Schemes
- Bit-Interleaved Coded Modulation for MIMO
- Spatial multiplexing (SM) schemes (ZF, MMSE, ML, VBLAST)
- Beamforming schemes (Instantaneous, Statistical (SB))
- Space-time block coding (STBC)
- Analysis Techniques
- BER expressions (with a case study)
- Multivariate statistics (Wishart matrices, Quadratic forms, ...)
- Moment generating functions (MGF)
- Practical Adaptive MIMO Schemes & Performance in Correlated Channels
- Uncoded (SM-STBC switching, multi-mode antenna selection, ...)
- Coded SM-SB switching
- Coded SM-STBC switching
Primary Audience
It will be of interest to both researchers and industry engineers.
Novelty
This tutorial focuses on practical MIMO channels, complete with correlation and rank deficiencies, and proposes new methods for adaptive switching to optimize performance. The methods are directly applicable to current and future standards, including IEEE 802.11n and IEEE 802.16.
Biography
Dr Iain B. Collings has held academic positions at the University of Melbourne and the University of Sydney, where he was an Associate Professor. Since August 2005 he has been the Science Leader in Communications and Signal Processing in the ICT Centre of the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia. He has published over 100 international journal and conference papers, and most recently has focused his research on the capacity and performance of MIMO systems in practical correlated environments. His other research interests include synchronization, channel estimation, equalization, and multi-carrier modulation, for time-varying and frequency-selective channels. He serves as an Editor for the IEEE Transactions on Wireless Communications, and was the Vice Chair of the Technical Program Committee (TPC) for the IEEE Vehicular Technology Conf. (Spring) 2006, amongst other activities. He is a Senior Member of the IEEE.
Dr Robert W. Heath Jr. has held senior positions in both industry and universities. From 1998-99 he was a Senior Member of the Technical Staff at Iospan Wireless Inc, San Jose, CA where he played a key role in the design and implementation of the physical and link layers of the first commercial MIMO-OFDM communication system. From 1999 to 2001 he served as a Senior Consultant for Iospan Wireless Inc. In 2003 he founded MIMO Wireless Inc. Since January 2002, he has
been with the Department of Electrical and Computer Engineering at The University of Texas at Austin where he serves as an Assistant Professor as part of the Wireless Networking and Communications Group. His research interests cover a broad range of MIMO communication including antenna design, practical receiver architectures, limited feedback techniques, ad hoc networking, and scheduling algorithms as well as 60GHz communication techniques. He serves as an Editor for the IEEE Transactions on Communication, an Associate Editor for the IEEE Transactions on Vehicular Technology, and is a member of the Signal Processing for Communications Technical Committee of the IEEE Signal Processing Society.
T6: Design and evaluation of antennas for communications with diversity and MIMO
Presenter: R. Vaughan
Time: PM
Room:
Abstract
Most antenna applications are for a digital communications link. The motivation comes from the antenna gain having a direct impact on the link performance including the spectral efficiency. We review the classical directive gain and its measurement with the natural progression to the distributed gain and the diversity gain for antennas designed for multipath situations. With most links operating in multipath, multi-element antennas with high distributed gain and good diversity performance are required.
Developing compact, multi-element antennas with statistical performance measures requires convenient experimental evaluation techniques. Antenna performance evaluation is not only part of the communications system analysis and design, but it is also part of the iterative process of compact antenna design. This is why having a quick performance evaluation estimate is particularly important. Both theoretical and practical aspects are addressed for evaluating antennas for high capacity efficiency. This calls for an emphasis the various efficiency and gain factors which feature in the multipath communications link analysis. Here, for example, the antenna polarization efficiency becomes incorporated into the distributed gain of the antenna element and this is a major difference between classical line-of sight links and diversity links for multipath. Finally, the compactness of an antenna system is important for both the cost of the terminal and its market acceptability. The trade-off between impedance bandwidth and antenna compactness offers a helpful comparison for different types of antenna elements. For evaluating multi-element antennas for multipath environments, the diversity gain offers a robust performance measure.
Tutorial Objectives
Link performance is normally measured by the throughput of correctly detected bits per bandwidth, or capacity efficiency. If the BER can be kept to less than about 10^{-4}, then FEC can reduce the coded bit error rate to a negligible value. For most wireless applications, an acceptable uncoded BER for can be as low as 10^{-3} or even 10^{-2}. With these numbers, a direct estimation of the capacity of a link, or its digital outage, etc., is relatively straightforward, involving a transmitted test sequence analysis. But such an evaluation deals with only the data channel and does not reveal the analogue mechanisms causing the bit errors, or where the most economical link design improvements could be made. While fractions of a dB improvement are a cause for celebration in coding research, the goal of the tutorial is for attendees to appreciate that much larger improvements in personal and nomadic links, can be often made at the antennas, through better matching (spatial, polarization and impedance), leading to higher gain designs. The objectives of the tutorial are to gain an understanding of the basic principles involved in the design of efficient antennas and their evaluation. These principles include the following.
* Impedance bandwidth and antenna compactness are fundamental trade-offs for compact elements. For arrays, the diversity gain is the important performance measure, and this also trades off with compactness. However, the diversity gain is a statistical quantity and its direct estimation requires an expensive measurement campaign with considerable a posteriori signal processing.
* Moreover, the diversity gain, alone, does not provide the specific information for how to improve the configuration of the antenna elements. The required information is contained in the set of mean branch powers and in particular the set of correlation coefficients between the loaded antenna signals. Direct estimates of these statistics would be made from sampling the antenna signals when the antenna is operating in different multipath scenarios. However, gathering and using such samples brings difficulties in the interpretation and repeatability, and the sample size required for accurate estimates is very large which again means an expensive measurement effort. These factors highlight a need for a more convenient evaluation technique, especially for the antenna design process, which is normally iterative.
* Measuring the antenna impedances, together with modest a posteriori processing, offers such an alternative, although this approach requires certain conditions regarding both the propagation environment and the antenna elements. If these conditions hold (which they do, for efficient designs), then the diversity gain can be estimated from the impedance measurement. For designing multi-element antenna configurations, the diversity gain can be couched as an equivalent number of ideal branches, i.e., an effective diversity order. The effective diversity order is a performance metric which allows the designer to control the trade-off against compactness of the multi-element antenna configuration.
* The concepts are illustrated through design examples in which the antenna is made sufficiently compact to force the effective order of diversity to be significantly less than the number of physical antennas.
Tutorial Outline
- 1. Introduction
- 1.1. Background: digital communications link performance
- 1.2. Interference-limited links
- 2. Basic antenna parameters and evaluation with ideal point-to-point
- 2.1. Directive gain
- 2.2. Antenna efficiency terms
- 2.3. Effective aperture and equivalent circuits
- 2.4. Impedance bandwidth and Q factor
- 2.5. Compactness evaluation
- 2.6. Free space links for gain measurement
- 2.7. Gain evaluation
- 2.8. Non-reciprocal antennas
- 2.9. Complex pattern cut measurement
- 2.10.Line-of-sight links
- 2.11.Mobile NLOS link
- 2.12.Scenario models for distributed gain estimation
- 2.13.Distributed source models
- 3. Gain factors for non-line-of-sight
- 3.1. Signal description of combining: no interference case
- 3.2. Many-branch complex Gaussian statistics
- 3.3. Sample sizes for estimating the mean power and the Gaussian correlation
- 3.4. Mutual coupling for diversity evaluation
- 3.5. Measurement transmission line calibration
- 3.6. Mutual coupling: network model
- 3.7. Loaded circuit and open circuit correlations
- 3.8. Received power for resistive loads and mutual coupling power loss
- 3.9. Diversity gain estimate
- 3.10.Examples
- 4. Summary
Primary Audience
This course will be of interest to graduate students in a communications option of electrical engineering and who are interested in the physical layer. Specifically, the antenna offers a place where relatively large performance gains can be made to existing systems, or help define the performance of newer multi-antenna systems. The course will also be of interest to engineers who are working with antenna evaluation for mobile terminals such as handhelds and laptops, and also basestations for small area coverage.
Novelty
With techniques such as equalization, rake, FEC, etc., wireless systems can now operate within fractions of a dB of their Shannon limit. In principle, signal processing capability has reached effective saturation of the Shannon capacity efficiency. The antenna gain has not only maintained its fundamental role in the wireless link, but the above sense, has now become the only capacity-enhancing block left for the system designer of a power-constrained link. This tutorial includes new techniques and results for the antenna.
Biography
Rodney Vaughan received his Bachelor and Masters degrees from the University of Canterbury, New Zealand, in 1975 and 1976 respectively, and the PhD from Aalborg University, Denmark, in 1985, all in Electrical Engineering. He worked with the New Zealand Post Office (now Telecom NZ Ltd) and the NZ Department of Scientific and Industrial Research (DSIR). He worked on a wide variety of mechanical and electrical projects including network analysis and traffic forecasting, and developed microprocessor and DSP technology for industrial equipment ranging from abattoir hardware to communications networks. He was an URSI Young Scientist in 1982 for Fields and Waves, and in 1983 for Electromagnetic Theory. In 1992, he transferred to Industrial Research Limited (NZ), where he developed research programmes on communications technology which were funded by the New Zealand Foundation for Research, Science and Technology. He undertook several research projects revolving around multipath theory (electromagnetic, line and acoustic media), diversity design, signal and sampling theory, and signal processing. Industrial projects have included the design and development of specialist antennas for personal, cellular, and satellite communications, MIMO test bed and systems design; and also capacity theory and spatial field theory for antenna design. Since 2003, he is Professor of Electrical Engineering and Sierra Wireless Senior Chair in Communications, at the School of Engineering Science, Simon Fraser University, British Columbia, Canada. Current projects are compact mammalian bio-implantable RF tags; multielement antenna design and evaluation; wire loop and slot antennas, multifaceted, circularly polarized, large array systems; MIMO capacity realization and precoding. He was co-guest-editor of the November 2006 IEEE Antennas and Propagation Transactions Special Issue on Wireless Communications. He is a Fellow of the B.C. Innovation Council, a Fellow of the IEEE, an URSI Correspondent, and is the New Zealand URSI Commission B (Fields and Waves) representative.
T7: Theoretical aspects of wireless sensors and ad hoc networks
Presenter: Prof Roberto Verdone (UoB, Italy), Dr Mischa Dohler (FTRD, France), and Prof Hamid Aghvami (KCL, UK)
Time: PM
Room:
Abstract
Sensor networks have been researched and deployed for decades already; their wireless extension, however, has witnessed a tremendous upsurge in recent years. This is mainly attributed to the unprecedented operating conditions of wireless sensor networks (WSNs), i.e. a potentially enormous amount of nodes operating under stringent energy constraints and characterised by strong limitations in terms of processing capabilities and device complexity.
The rich mathematical and technical toolboxes already available from the design of wireless cellular and ad hoc systems clearly aided the birth of new ideas tailored to the problems in WSNs, although many relevant aspects of WSNs are not common to ad hoc networks, and vice-versa. This makes the design of communication and data processing techniques used in WSNs sometimes very different from the case of ad hoc networks. It is therefore crucial to highlight the differences and commonalities.
The aim of this tutorial is to expose an industrial and academic audience to the challenges related to the analysis, design and deployment of such recently emerged networks at PHY, MAC and network layers - with particular emphasis on cross-layer and cross-functionality optimisation. To this end, the tutorial is conveyed in two mutually harmonised parts: the first part deals with fundamental issues at mainly PHY and MAC layers and presents techniques suitable for both WSNs and ad hoc networks, whereas the second part focuses on MAC and network aspects that are specific to WSNs.
Tutorial Objectives
We will commence with a plethora of application and deployment scenarios for which wireless sensor and ad hoc networks are beneficial. We will briefly dwell on major design differences between WSNs and traditional ad hoc networks, which will be further elaborated on in the afternoon. We will then continue with a brief summary of the historical developments related to WSNs at various layers, including recent developments in distributed and cooperative networks. Capacity and transceiver performance analysis strongly depends on the underlying channel models. This part of the tutorial hence endeavours to introduce some suitable channel models which correctly reflect the underlying communication scenarios. The information theoretical limits of large-scale, potentially distributed and cooperative, systems are then revised in simple and understandable terms without requiring a strong background in information theory. Emphasis will be put onto the ergodic and outage capacities assuming a variety of channels and various degrees of imperfections. This will prove vital in comparing the performance of realistic distributed transceiver structures to the predicted bounds. The capacity bounds can only be approached by appropriate code design, where we will elaborate on the theory of space-time coding, also from a distributed and cooperative network point of view and their ability to be deployed within WSNs. To this end, space-time code design criteria are exposed, as well as closed form expressions and upper bounds for the error performance of space-time encoded distributed relaying networks given. The error rates of various distributed transceiver schemes are compared and tendencies explained. Finally, suitable MACs for energy constrained, possibly distributed and cooperative, WSNs will be introduced and analysed. In particular, the advantages and disadvantages of reservation-based and random medium access control protocols will be compared. Furthermore, cross-layer design guidelines will be given, where PHY-layer specific parameters are incorporated into the MAC, so as to optimise throughput and latency.
We will then deal with some statistical models that can provide useful general insights on the way to dimension the node density in WSNs, given some requirements on the coverage and connection probability. This part will be mainly based on theoretical work, and comparison to simulation. The issue of Coverage will also be treated jointly. Some general lessons will be learned, that are useful to understand some general principles of WSAN design. A survey on the literature will be included. Network lifetime is dealt with next. This part will describe the models available for battery energy consumption, the definitions of network lifetime, which will be discussed and compared. This is followed by case studies. This part will give an example of the methodology used to design a WSAN, describing the scenario, the measurements done, the design methodology used, and providing samples of the measurements performed over the field. Simulation and Measurement results will be shown. Finally, conclusions are drawn and design guidelines for connectivity, coverage and network lifetime issues are given. Important open research topics for academia and industry are suggested.
Tutorial Outline
- I. Distributed Cooperative Communication Techniques.
- I.1. Scenarios.
- I.2. Background.
- I.3. Channel Models.
- I.4. Shannon Capacity.
- I.5. Transceiver Design.
- I.6. Medium Access Control.
- II. Connectivity, Coverage and Network Lifetime
- II.1. Introduction.
- II.2. Connectivity and Coverage.
- II.3. Network Lifetime.
- II.4. Case Study(ies).
- III. Final Remarks & Design Guidelines.
Primary Audience
This tutorial is tailored to the level of practicing engineers and advanced researchers who are interested in the fundamentals and design of future generation communication networks involving wireless sensor networks and novel non-centralised communication paradigms of distributed and cooperative communication.
The attendee is expected to be well equipped in the functioning and understanding of modern communication systems. Knowledge in information theory, channel modelling, space-time code design and medium access control is advantageous but not vital. The tutorial presenters will endeavour to make the presentation self-consistent.
Novelty
Currently, this is the only tutorial which gives a coherent view on the operation of a energy constrained large-scale wireless sensor network, which uses distributed and cooperative techniques to enhance its performance. The tutorial has been very well received in the past years, also because the presenters constantly update their presentation contents.
Also, the tutorial presenters will profit from their experiences with companies who did real-world WSN roll-outs to pin-point real design problems, which are sometimes quite different from the ones assumed in the open literature and require shifts in design paradigms.
Biography
Roberto Verdone was born in Bologna, Italy, on August 6, 1965.
He received the Laurea degree in Electronic Engineering and his Ph.D. from the University of Bologna in 1991 and 1995, respectively.
Since 2001 he is Full Professor in Telecommunications at the University of Bologna and joined the Department of Electronics, Computer Science and Robotics (DEIS). Since 1996 to 2001 he was a researcher at CSITE (a research centre of the National Research Council, CNR), now IEIIT-BO, in Telecommunications. He still collaborates to IEIIT-BO activities. He participates to WiLAB (Wireless Communications Laboratory).
Mischa Dohler obtained his MSc in Telecoms from King's College London in 1999, his Diploma from Dresden University of Technology, Germany, in 2000, and his PhD from King's College London in 2003. He has been lecturer at King's College London until June 2005. He is now Senior Research Expert in the R&D department of France Telecom working on cognitive, distributed and cooperative systems. Prior to Telecommunications, he studied Physics in Moscow. He has won various competitions in Mathematics and Physics, and participated in the 3rd round of the International Physics Olympics for Germany. He has published over 80 technical journal and conference papers, holds several patents, co-edited and contributed to several books, and has given numerous international short-courses. He has been TPC member and co-chair of various conferences and is editor of the EURASIP journal, IEEE Comms Letters and IEEE TVT. He has given numerous international tutorials.
Hamid Aghvami is presently the Director of the Centre for Telecommunications Research at King’s College London. He has published over 300 technical papers and given invited talks all over the world on various aspects of mobile communications as well as giving courses on the subject world wide. He is a distinguished lecturer and a member of the Board of Governors of the IEEE Communications Society. He has been member, Chairman, Vice-Chairman of the technical programme and organising committees of a large number of international conferences. He is also founder of PIMRC & ICT. He is a Fellow of the Royal Academy of Engineering, and Fellow of the IEEE and IEE.
T8: Next-generation wireless multimedia transceivers in the turbo era
Presenter: Lajos Hanzo, University of Southampton
Time: PM
Room:
Abstract
Wireless multimedia communication devices are becoming ever more powerful and sophisticated, as seen on television. Nonetheless, the provision of realistic ``tele-presence'' services requires a further quantum leap from the current state-of-the-art represented by the popular mobile telephone. Based on the presenter's monographs and papers (www.ecs.soton.ac.uk/people/lh and www-mobile.ecs.soton.ac.uk) recent advances in this challenging field are reviewed, commencing with a brief portrayal of the related multimedia source codecs, advanced channel codecs and burst-by-burst adaptive modems, such as those used by the High-Speed Downlink Packet Access (HSDPA) mode of the third-generation (3G) wireless systems, including space time codecs and other MIMO systems.
Commencing with a review of the Shannonian information-theoretic design principles, powerful system design examples will be presented. The limitations of the Shannonian lessons in the context of realistic fading, rather than Gaussian channels will be detailed. To elaborate a little further, most multimedia source signals are capable of tolerating lossy, rather than lossless delivery to the human eye, ear and other human sensors. The corresponding lossy and preferably low-delay multimedia source codecs however exhibit unequal error sensitivity, which is not the case for Shannon's ideal entropy codec.
Numerous jointly optimised iterative turbo transceiver designs capable of providing unequal error protection for MPEG-4 coding aided wireless video telephony and audio transmission will be highlighted, which exhibit a performance close to the channel capacity. EXIT charts will be used for designing these sophisticated multi-stage iterative transceivers.
Tutorial Objectives
More and more business as well as personal users are relying
on employing wireless multimedia communications for a variety of applications. This course reviews the most recent research trends, source compression and channel coding as well as turbo detection techniques and system components in the field of wireless multimedia communications.
The learning objectives are:
o review the related Shannonian lessons
o become familiar with the research trends of wireless multimedia systems
o understand the limitations and design constraints of wireless multimedia systems
o become aware of powerful HSDPA-style burst-by-burst adaptive modulation and transmission techniques in the context of single- and multi-carrier or OFDM systems as well as multi-user detection aided CDMA
o cover the basics of jointly optimised multimedia turbo transceivers
o familiarisation with the basic features of state-of-the-art voice and video source codecs and system design principles
Tutorial Outline
- 1. The Shannonian Lessons
- 2. HSDPA-style burst-by-burst adaptive multimedia transceivers
- 3. Multi-stage multimedia turbo transceiver design
- 3.1 Turbo-Detected Unequal Protection MPEG-4 Wireless Video Telephony
- using Multi-Level Coding, Trellis Coded Modulation and Space-Time
- Trellis Coding
- 3.2 Turbo-Detected Unequal Error Protection Irregular Convolutional Codes Designed for the Wideband Advanced Multirate Speech Codec
- 4. Transceiver design guidelines
Primary Audience
This overview was designed to appeal to a wide range of audience,
requiring a modest background in signal processing and communications. Accordingly, research and development engineers, telecommunications managers, consultants, academic researchers and other technical personnel may find the wide coverage of the overview attractive.
Novelty
The novelty of this overview is that the Shannonian source- and channel coding separation theorem is revisited in the context of realistic, finite-delay, finite-complexity multimedia source codecs combined with
powerful wireless turbo transceivers. The bold message is that under these realistic conditions the modern psycho-acoustically and psycho-visually designed 'lossy' low-rate multimedia turbo transceivers communicating over fading, rather than Gaussian channels are rather different from the potentially high-delay lossless Shannonian schemes designed for Gaussian channels.
Biography
Lajos Hanzo (FREng, FIEEE, FIET, DSc)
http://www-mobile.ecs.soton.ac.uk; www.ecs.soton.ac.uk/people/lh
has held various research and academic posts in Hungary, Germany and the UK. Since 1986 he has been with the School of ECS, University of Southampton, UK, where holds the Chair in Telecommunications. He
co-authored 14 IEEE Press - John Wiley books totalling 9000 pages on mobile radio communications, published in excess of 650 research papers, was TPC Chair of several IEEE conferences> He is the presenter
of numerous keynote lectures and has been awarded a number of
distinctions. He is an enthusiastic supporter of industrial-academic liaison and he offers a range of industrial courses. Lajos is also an IEEE Distinguished Lecturer of both the Communications
as well as the Vehicular Technology Society and Governor of the IEEE
VTS.
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