Cognitive Radio and Advanced Spectrum Management  

Presenter:  Dr. Rashid Abdelhaleem Saeed

Dr. Rashid A. Saeed has been a research scientist in wireless network and protocol research lab (WNPR) at MIMOS Berhad at Technology Park Malaysia (TPM) since 2007, where he has been involved in research, development, design, and prototyping in wireless communications systems, including WiMAX and WLAN heterogeneous networks, wireless mesh network and IMT-Advanced. He received his Ph.D. in communications Network engineering from Universiti Putra Malaysia (UPM) in 2007. He is a WiMAX certified RF network engineer (ID: WFRE355) from WiMAX forum. His research interests are wireless broadband, cognitive radio and OFDMA techniques. He has published more than 30 research papers/tutorials on wireless communications and networking in peer-reviewed academic journals and conferences, and has been awarded 5 patents in these areas. Rashid is a MIEEE since 2001 and Incorporated Member IEM (Inc. I.E.M). He is executive committee - Program Chair in Communication Society (ComSoc), IEEE Malaysian chapter. He is a member of the IEEE ComSoc Certification in Wireless Communications Engineering Technology (WCET), where he has been involved in the questions writing and reviewing in fields of Network and Service Architecture, Wireless Access technologies, and polices and standards.

Description: Spectrum access, efficiency, and reliability have become critical public policy issues. Recent study by FCC Spectrum-Policy Task Force (SPTF) found that while the available spectrum becomes increasingly scarce, the assigned spectrum is significantly underutilized. The term Cognitive Radio was first defined by Mitola in 1999. Cognitive radio is a novel technology, which improves the spectrum utilization by seeking and opportunistically utilizing radio resources in time, frequency and space domains on a real time basis. It refers to a new type of radio hat uses real-time interaction with its environment to determine transmitter parameters such as frequency, power, and modulation. The cognitive radio technology poses many new technical challenges, and overcoming these issues becomes even more challenging due to non-uniform spectrum and other radio resource allocation policies, economic considerations, the inherent transmission impairments of wireless links and user mobility. Cognitive radio technology advances are based on interdisciplinary research, including among others: signal processing, information theory, communications engineering, artificial intelligence, game theory and economics. Many case studies and examples will be investigated i.e. ultra-wide bandwidth technology as a transmission technique suitable for implementing a cognitive radio system, and a comparable measurement of TV spectrum band in an urban environment is another example. 

Outline: Topics that will cover in the tutorial include: Dynamic spectrum sharing and Dynamic Frequency Selection (DFS) techniques and policies; Interoperability, interference and co-existence of dissimilar wireless networks; Spectrum measurements and sensing; PHY layer design for cognitive radio; Ultra-Wideband cognitive radio system, wide-band spectrum sensing and Multi-band, spectrum-agile and adaptive radio transceivers; Interference metrics and measurement; Cognitive protocols and algorithms from PHY to application layer; Cross-layer cognitive algorithms; Application of machine learning and policy processing to cognitive radio; Business and regulatory aspects of spectrum usage reform; Software-defined radio; Implementation, standardization, and certification of cognitive radio; and Cognitive radio prototypes. 

Advanced Optical Communication System Design  

Presenter:  Prof. Dr.-Ing. Werner Rosenkranz 

Werner Rosenkranz studied Electrical Engineering at the University of Erlangen-Nurnberg, Erlangen, Germany. There he received the Ph.D. and the Habilitation at the Lehrstuhl für Nachrichtentechnik. He worked on Phase-locked Loops, digital FM-systems, and Digital Signal Processing. In 1989 he joined Philips Kommunikations Industrie and Lucent Technologies in Nuremberg, Germany, where he was responsible for a transmission group in the basic development team. In 1997 he became Professor and holds since then the Chair for Communications in the Department of Engineering of the University of Kiel, Germany. His main research activities are transmission-aspects in digital communication systems with focus on optical transmission, synchronization systems, and simulation. He is author or coauthor of more than 150 publications on selected topics as e.g. compensation and equalization of optical transmission channels, advanced modulation formats in optical communications, high-speed transmission, modeling of channel impairments etc. Prof. Rosenkranz is a member of IEEE and VDE and ITG.

Description: The optical communications industry adopts more and more the successful concepts of digital communications in their high capacity transmission networks. Whereas simple approaches like on-off keying/direct detection schemes were sufficient for up to 10Gb/s channel capacity, we introduce more advanced system designs also in the optical environment due to cost and/or capacity constraints. Advanced modulation formats (e.g. QPSK, duobinary, etc.), channel coding (FEC e.g. based on Reed-Solomon codes, etc.), equalizers (simple linear zero forcing equalizers up to detectors based on MLSE (Viterbi) algorithm) are examples of these new approaches. Although well known and widely used in copper based and wireless transmission, these concepts are extremely challenging due to the very high speed requirements and the specific channel impairments in optical communications. Recent developments employ pure digital processing, where very fast A/D and D/A converters are required. Examples are OFDM (orthogonal frequency division multiplexing) modulation, MLSE (maximum likelihood sequence estimation) equalizers or complex signal processing in order to achieve clock-and carrier recovery, polarization control and equalization in coherent optical receivers. In this tutorial some of these signal processing algorithms are considered in detail and their impact on performance and cost in terms of implementation effort is reviewed. 

Outline: 1. Optical transmission links and networks basics. WDM. Basic transmitter and receiver design (basic laser characteristics, modulators, optical front end). 2. Review of the optical transmission channel. Impairments and models based on system theory (dispersion, PMD, nonlinear effects, WDM specific crosstalk and intermodulation). 3. Advanced optical modulation formats (duobinary, DPSK, SSB, multi-level formats). 4. Equalizers for the optical channel impairments (FFE, DFE, nonlinear Volterra based equalizers, MLSE). 5. Most recent achievements and challenges: 100Gb/s Ethernet, optical OFDM and Digital signal processing in transceivers for 100Gb/s Ethernet: Design example - Coherent QPSK with polarization multiplexing of 2x28GBaud. 6. Summary, Wrap-up.

Multi-antenna and Multi-carrier Next Generation Mobile Communications Systems

Presenters:  Dr. F. Rodrigo P. Cavalcanti, Dr. Walter F. Cruz Jr. and Dr. Charles C. Cavalcante 

Francisco Rodrigo Porto Cavalcanti obtained his doctorate in Electrical Engineering from State University of Campinas, Brazil, in 1999. Nowadays, he is associate professor at Federal University of Ceara (UFC). He established and manages GTEL – Grupo de Pesquisa em Telecomunicações Sem Fio, which is a research institute focused on the advance of wireless communications technologies. He manages a research program on wireless communications founded by Ericsson of Brazil at GTEL since 2000, where software, patents, models and solutions for 3rd and 4th wireless communications systems have been generated. He focuses on two big research lines: signal processing for wireless communications and radio resource management. He published more 100 papers on conferences and scientific magazines regarding themes like power control, radio resource management, performance evaluation of GSM/GPRS/EDGE/WCDMA/HSDPA cell systems, adaptive antennas, MIMO, OFDM and QoS for wireless IP, among others. He is certificated in Leadership and Management by Massachusetts Institute of Technology (MIT, 2008) and Project Management Professional (PMP) by Project Management Institute (PMI, 2005).

Walter Freitas Cruz Jr. is graduated on Electrical Engineering by Federal University of Ceara (UFC, 2000). He has also from Federal University of Ceara a master degree (UFC, 2002) and a doctorate degree (2006). He was a researcher on Instituto Nokia de Tecnologia (INdT) and actually he is a researcher on GTEL, where he works on resource allocation for MIMO-OFDMA systems. He is associated to Departamento de Teleinformática (DETI) of Federal University of Ceara where he teaches Mobile Communications Systems and Cooperative Wireless Networks disciplines. He is a referee for IEE Proceedings - Communications do Institution of Electrical Engineers and for important conference in the area. Also he is a member from Sociedade Brasileira de Telecomunicações e Institute of Electrical and Electronics Engineers, Inc. He was a sponsorship from Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (FUNCAP) at Ceara State. His main interests are: space time coding, MIMO systems, OFDM systems, MIMO-OFDM systems, resource allocation on MIMO-OFDM and link adaptation.  

Charles Casimiro Cavalcante obtained his BSc. and MSc. degrees from Federal University of Ceara (UFC) in 1999 and 2001, respectively, and in 2004 his doctorate degree at State University of Campinas. He was a CNPq/DCR level 2A researcher at Departamento de Engenharia de Teleinformática (DETI) of UFC from May 2004 to April 2007. Since 2007, he is a Visiting Professor at DETI-UFC. He is a member and a researcher of GTEL where he develops researches related to signal processing application to communications and physical layer optimization of wireless communications systems in association with private partners and in projects founded by federal agencies. He published approximately 40 papers on magazines and conferences. He is also manager of research projects at GTEL regarding contemporary  mobile communication systems, which are developed together with Ericsson Research. He taught several short courses and invited talks regarding signal processing and communications at national and international conferences in the last five years. His research areas are: signal processing, space time coding and statistical signal processing. 

Description: Mobile telephony and Internet convergence is a process that is becoming more intense in the last years.  Post 3rd generation mobile networks allow data traffic over packets through infrastructure convergence using “All-IP” concept., where radio access uses native IP protocol. The desired convergence depends on allowing multiple services with different performance and quality requirements. IP networks don’t provide native QoS mechanisms, requiring its implementation at network nodes. Also, the arising of wireless Internet access with same quality and experience requirements of traditional cooper or fiber accesses represents a technical challenge, since new information transmission mechanisms are need to provide transmission rates 1 up to 2 magnitude orders higher. Among emergent system there is an 3GPP (Third Generation Partnership Project) proposal known as LTE (Long-Term Evolution), which aims to evolving GSM-GPRS-EDGE-WCDMA-HSPA systems family. LTE and other next generation wireless access networks take advantage of digital modulations and OFDM. The available bandwidth is divided on several narrowband subcarriers, which in turn could have rate and power adapted according on link quality. So, adaptive modulation and coding techniques allow the “marriage” of available spectral efficiency with link condition. MIMO (Multiple Input Multiple Output) techniques employ multiple antennas at transmitter and receiver aiming to maximize spatial diversity gain. Through these mechanisms it is possible to improve link robustness against fading and to send more information on multiple parallel spatial sub channels , at same time, increasing link capacity. Therefore, signal processing techniques are necessary to cancel the  interference caused by the channel. MIMO and OFDM combination forms a technological couple that enables a significant increasing on the transmission rate  of LTE and similar systems, from 100 Mbps with mobility and with peak rate of 1 Gbps on stationary conditioning. This tutorial proposes to discuss about the fundamentals and advanced aspects regarding MIMO and OFDM based transceptors. A review about the main OFDM concepts and MIMO structures will be done separately to allow the public a greater familiarization with the problem. In sequence, it will be described some hybrid structures that allow to take advantage of both gains: multiplexing and diversity. Finally, aspects related to OFDM-MIMO fusion are explored to evidence its advantages and also to detach the challenges at modern mobile communications systems. More advanced aspects regarding physical and access layers that enable high capacity and QoS satisfactory at these systems. Cross-layer optimization is discussed against  traditional approach, pointing enhancements that could increase wireless systems performance. Still, we will present a study regarding Web and VoIP traffic dimensioning to achieve QoS at the same time in emergent wireless systems. 

Outline: Part I – OFDM Access and Resource Allocation. 1. Introduction to OFDM and LTE System. 2. OFDMA and radio resource management. 3. Web and VoIP Service Operation over Wireless Systems. Part II – MIMO-OFDM Transceptors and Cross-layer. 1. MIMO Structures. 2. MIMO-OFDM Structures. 3. Cross-layer Optimization.