Tutorials

T1 - Massive MIMO – Fundamentals, Trends and Recent Developments

Speakers:

Emil Björnson
Linköping University, Sweden

Luca Sanguinetti
University of Pisa, Italy

Schedule

TBA

Summary

Multiuser MIMO (MU-MIMO) technology consists of using multiple jointly processed antennas at the infrastructure side to separate interference in the spatial domain, allowing multiple users to send (uplink) or receive (downlink) data simultaneously, on the same time-frequency slot. While MU-MIMO is theoretically well-understood and has been around for decades, only relatively recently it has overcome practical implementation skepticism, and has become a mainstream technology. An important step forward, that pushed industry to widely embrace MU-MIMO, is the introduction of the concept of “Massive MIMO”. This consists of a particular regime of MU-MIMO where the number of base station antennas is much larger than the number of simultaneously transmitted data streams. Everybody talks about Massive MIMO, but do they all mean the same thing? What is the canonical definition of Massive MIMO? What are the differences from the classical MU-MIMO technology from the nineties? How does the channel model impact the spectral efficiency? How can Massive MIMO be deployed and what is the impact of hardware impairment? Is pilot contamination a problem in practice?

This first half of this tutorial aims to answer all the above questions and to explain why Massive MIMO is a promising solution to handle several orders-of-magnitude more wireless data traffic than today’s technologies. The second half reviews the most significant trends that are pushing the original Massive MIMO ideas in different directions, including: the key role of Massive MIMO when designing cellular networks that are highly energy efficient; how Massive MIMO makes more efficient use of the hardware, which opens the door for using component with lower resolution; an overview of important practical aspects, such as power allocation, pilot assignment, scheduling, load balancing, channel modeling, array deployment, and the role of Massive MIMO in heterogeneous networks.

Biography

Emil Björnson has a 10-years’ experience on multi-user MIMO research. His expertise has been acknowledged by 5 best paper awards on multi-user MIMO technology and by a handful of related patent applications. He received the Ph.D. degree from the KTH Royal Institute of Technology, Sweden, in 2011. From 2012 to July 2014, he was a postdoc at Supélec, France. He joined Linköping University, Sweden, in 2014 and is currently an Associate Professor at the Division of Communication Systems. He received the 2016 Best PhD Award from EURASIP, the 2015 Ingvar Carlsson Award, and the 2014 Outstanding Young Researcher Award from IEEE ComSoc EMEA. He is the first author of the magazine article “Massive MIMO: Ten Myths and One Critical Question” (2016), the textbook “Optimal Resource Allocation in Coordinated Multi-Cell Systems” (2013) and "Massive MIMO Networks: Spectral, Energy, and Hardware Efficiency". He is dedicated to reproducible research and has made a large amount of simulation code publicly available. His research interests include multi-antenna cellular communications, Massive MIMO technology, radio resource allocation, energy efficient networking, and hardware-impaired communications. He is on the editorial board of the IEEE Transactions on Communications (since 2017) and the IEEE Transactions on Green Communications and Networking (since 2016).

L. Sanguinetti is an Assistant Professor in the Dipartimento di Ingegneria dell’Informazione of the University of Pisa. He received the Telecommunications Engineer degree (cum laude) and the Ph.D. degree in information engineering from the University of Pisa, Italy, in 2002 and 2005, respectively. In 2004, he was a visiting Ph.D. student at the German Aerospace Center (DLR), Oberpfaffenhofen, Germany. During the period June 2007 - 2008, he was a postdoctoral associate in the Department of Electrical Engineering at Princeton. Since July 2013, he is also with CentraleSupelec, Paris, France. He is serving as an Associate Editor for IEEE Trans. Wireless Commun. and IEEE Signal Process. Lett. He is the Lead Guest Associate Editor for IEEE JSAC - Game Theory for Networks. From June 2015 to June 2016, he was in the editorial board of IEEE JSAC - Series on Green Commun. and Networking. Dr. Sanguinetti served as Exhibit Chair of ICASSP14 and as the general co-chair of the 2016 Tyrrhenian Workshop on 5G&Beyond. He is a co-author of the textbook ``Massive MIMO Networks: Spectral, Energy, and Hardware Efficiency’’ (2017). His expertise and general interests span the areas of communications and signal processing with special emphasis on multiuser MIMO, game theory and random matrix theory for wireless communications. He was the co-recipient of 2 best paper awards: IEEE Wireless Commun. and Networking Conference (WCNC) 2013 and IEEE Wireless Commun. and Networking Conference (WCNC) 2014. He was also the recipient of the FP7 Marie Curie IEF 2013 “Dense deployments for green cellular networks”. Dr. Sanguinetti is a Senior IEEE Member.

T2 - Engineering Wireless Full-Duplex Nodes and Networks

Speaker:

Melissa Duarte
Huawei Technologies, France

Schedule

TBA

Summary

A full-duplex wireless transceiver node can transmit and receive at same time and in the same frequency band. In contrast, Time Division Duplex (TDD) and Frequency Division Duplex (FDD) transceiver nodes cannot realize simultaneous bidirectional in-band communication because they use orthogonal time and orthogonal frequency resources respectively. Consequently, networks where all or some of the nodes are full-duplex capable can potentially achieve higher spectral efficiency than TDD and FDD networks. This is the main motivation for the deployment of full-duplex nodes. However, implementing full-duplex capable transceivers requires the mitigation of the self-interference signal, with a power level several orders of magnitude larger than the received power of the signal of interest coming from a distant node. Recently, different research groups have demonstrated the feasibility of substantial self-interference mitigation that enables the realization of full-duplex communications with higher spectral efficiency than TDD and FDD systems. These demonstrations have motivated research in the area of full-duplex wireless communications and have made full-duplex a candidate technology for next generation wireless networks.

The recent increasing amount of research on full-duplex systems has resulted in a variety of methods for self-interference mitigation and of protocol designs for networks with full-duplex nodes. In this tutorial, we present the state-of-the-art of full-duplex technology and give insight about potential applications in future 5G cellular networks and 802.11ax WLAN. Attendees will learn about the challenges that need to be overcome at the RF level, physical layer level, and network level, in order to enable full-duplex wireless communication systems. The tutorial targets a broad audience with the aim that attendees with different backgrounds can understand the overall challenges of full-duplex system design as well as potential benefits. The tutorial will present main to-date results and will highlight some of the aspects that need to be addressed by future research.

Biography

Melissa Duarte received her B.Sc. degree in Electrical Engineering from the Pontificia Universidad Javeriana, Bogota, Colombia, in 2005. She received her M.Sc. and Ph.D. degrees in Electrical and Computer Engineering from Rice University, Houston, TX, in 2007 and 2012 respectively. From 2012 to 2013 she was a postdoctoral researcher at the School of Computer and Communication Sciences, EPFL, Lausanne, Switzerland. She is currently a research engineer at the Mathematical and Algorithmic Sciences Lab, Paris Research Center, Huawei Technologies Co. Ltd. Her Ph.D. thesis entitled “Full-duplex Wireless: Design, Implementation and Characterization” received the Rice University Electrical and Computer Engineering Department Best Dissertation Award, 2012. She holds two US Patents, one of them on a “System and Method for Full-Duplex Cancellation”. She received the ACM MobiHoc 2013 Best Paper Award and the 2017 Jack Neubauer Memorial Award recognizing the Best Systems Paper published in the IEEE Transactions on Vehicular Technology. Her research interests include the design and implementation of architectures for next-generation wireless communications. Specific interests and expertise include the areas of full-duplex wireless systems, cooperative relaying based networks, Multiple Input Multiple Output antenna (MIMO) systems, multi-carrier systems (OFDM), Software-Defined Radio (SDR), channel modeling for wireless systems, over-the-air measurements and experiments for the evaluation of wireless networks.

T3 - NOMA for Next Generation Wireless Networks: State of the Art, Research Challenges and Future Trends

Speaker:

Zhiguo Ding
Lancaster University, UK

Schedule

TBA

Summary

Non-orthogonal multiple access (NOMA) is an essential enabling technology for the fifth generation (5G) wireless networks to meet the heterogeneous demands on low latency, high reliability, massive connectivity, improved fairness, and high throughput. The key idea behind NOMA is to serve multiple users in the same resource block, such as a time slot, subcarrier, or spreading code. The NOMA principle provides a general framework, where several recently proposed 5G multiple access techniques can be viewed as special cases. Recent demonstrations by industry show that the use of NOMA can significantly improve the spectral efficiency of mobile networks. Because of its superior performance, NOMA has been also recently proposed for downlink transmission in 3rd generation partnership project long-term evolution (3GPP-LTE) systems, where the considered technique was termed multiuser superposition transmission (MUST). In addition, NOMA has been included into the next generation digital TV standard, e.g. ATSC (Advanced Television Systems Committee) 3.0, where it was termed Layered Division Multiplexing (LDM). This tutorial is to provide an overview of the latest research results and innovations in NOMA technologies, where various signal processing algorithms and transceiver designs in NOMA systems will be also introduced. Future research challenges regarding NOMA in 5G and beyond are also presented.

Biography

Zhiguo Ding received his B.Eng in Electrical Engineering from the Beijing University of Posts and Telecommunications in 2000, and the Ph.D degree in Electrical Engineering from Imperial College London in 2005. From Jul. 2005 to Aug. 2014, he was working in Queen’s University Belfast, Imperial College and Newcastle University. Since Sept. 2014, he has been with Lancaster University as a Chair Professor in Signal Processing. From Sept. 2012 to Sept. 2017, he is also an academic visitor in Princeton University working with Prof. Vincent Poor. Prof. Ding’s research interests are 5G networks, game theory, cooperative and energy harvesting networks, and statistical signal processing. He is serving as an Editor for IEEE Transactions on Communications, IEEE Transactions on Vehicular Networks, IEEE Wireless Communication Letters, IEEE Communication Letters, and Journal of Wireless Communications and Mobile Computing. He was the TPC Co-Chair for the 6th IET International Conference on Wireless, Mobile & Multimedia Networks (ICWMMN2015), Symposium Chair for International Conference on Computing, Networking and Communications (ICNC 2016), and the 25th Wireless and Optical Communication Conference (WOCC), and Co-Chair of WCNC-2013 Workshop on New Advances for Physical Layer Network Coding. He received the best paper award in IET Comm. Conf. on Wireless, Mobile and Computing, 2009 and the 2015 International Conference on Wireless Communications and Signal Processing (WCSP 2015), IEEE Communication Letter Exemplary Reviewer 2012, and the EU Marie Curie Fellowship 2012-2014.

T4 - Wireless Communications and Networking with Unmanned Aerial Vehicles

Speaker:

Walid Saad
Virginia Tech, USA

Schedule

TBA

Summary

Unmanned aerial vehicles (UAVs) are expected to become an integral component of future smart cities. In fact, UAVs are expected to be widely and massively deployed for a variety of critical applications that include surveillance, package delivery, disaster and recovery, remote sensing, and transportation, among others. More recently, new possibilities for commercial applications and public service for UAVs have begun to emerge, with the potential to dramatically change the way in which we lead our daily lives. For instance, in 2013, Amazon announced a research and development initiative focused on its next-generation Prime Air delivery service. The goal of this service is to deliver packages into customers' hands in 30 minutes or less using small UAVs, each with a payload of several pounds. 2014 has been a pivotal year that has witnessed an unprecedented proliferation of personal drones, such as the Phantom and Inspire from DJI, the Lone Project from Google, AR Drone and Bebop Drone from Parrot, and IRIS Drone from 3D Robotic. Such a widespread deployment of UAVs will require fundamental new tools and techniques to analyze the possibilities of wireless communications using UAVs and among UAVs. In the telecom arena, flying drones are already envisioned by operators to help provide broadband access to under-developed areas or provide hot-spot coverage during sporting events. More generally flying drones are expected to become widespread in the foreseeable future. These flying robots will develop a unique capability of providing a rapidly deployable, highly flexible, wireless relaying architecture that can strongly complement small cell base stations. UAVs can provide “on-demand” densification, help push content closer to the end-user at a reduced cost and be made autonomous to a large extent: Airborne relays can self-optimize positioning based on safety constraints, learning of propagation characteristics (including maximizing line of sight probability) and of ground user traffic demands. Finally UAVs can act as local storing units making smart decisions about content caching. Thus airborne relays offer a promising solution for ultra-flexible wireless deployment, without the prohibitive costs related to fiber backhaul upgrading. Yet another example is when UAVs can be used as flying base stations that can be used to serve hotspots and highly congested events, or to provide critical communications for areas in which no terrestrial infrastructure exists (e.g., in public safety scenarios or in rural areas). Clearly, UAVs will revolutionize the wireless industry and there is an ever increasing need to understand the potential and challenges of wireless communications using UAVs.

To this end, this tutorial will seek to provide a comprehensive introduction to wireless communications using UAVs while delineating the potential opportunities, roadblocks, and challenges facing the widespread deployment of UAVs for communication purposes. First, the tutorial will shed light on the intrinsic properties of the air-to-ground and air-to-air channel models while pinpointing how such channels differ from classical wireless terrestrial channels. Second, we will introduce the fundamental performance metrics and limitations of UAV-based communications. In particular, using tools from communication theory and stochastic geometry, we will provide insights on the quality-of-service that can be provided by UAV-based wireless communications, in the presence of various types of ground and terrestrial networks. Then, we will analyze and study the performance of UAV-to-UAV communications. Subsequently, having laid the fundamental performance metrics, we will introduce the analytical and theoretical tools needed to understand how to optimally deploy and operate UAVs for communication purposes. In particular, we will study several specific UAV deployment and mobility scenarios and we will provide new mathematical techniques, from optimization, game, and probability theory that can enable one to dynamically deploy and move UAVs for optimizing wireless communications. Moreover, we will study, in detail, the challenges of resource allocation in networks that rely on UAV-based communications. Throughout this tutorial, we will highlight the various performance tradeoffs pertaining to UAV communications ranging from energy efficiency to mobility and coverage. The tutorial concludes by overviewing future opportunities and challenges in this area.

Biography

Walid Saad received his Ph.D degree from the University of Oslo in 2010. Currently, he is an Associate Professor at the Department of Electrical and Computer Engineering at Virginia Tech, where he leads the Network Science, Wireless, and Security (NetSciWiS) laboratory, within the Wireless@VT research group. His research interests include wireless networks, machine learning, game theory, cybersecurity, unmanned aerial vehicles, and cyber-physical systems. Dr. Saad is the recipient of the NSF CAREER award in 2013, the AFOSR summer faculty fellowship in 2014, and the Young Investigator Award from the Office of Naval Research (ONR) in 2015. He was the author/co-author of six conference best paper awards at WiOpt in 2009, ICIMP in 2010, IEEE WCNC in 2012, IEEE PIMRC in 2015, IEEE SmartGridComm in 2015, and EuCNC in 2017. He is the recipient of the 2015 Fred W. Ellersick Prize from the IEEE Communications Society. From 2015-2017, Dr. Saad was named the Stephen O. Lane Junior Faculty Fellow at Virginia Tech and, in 2017, he was named College of Engineering Faculty Fellow. He currently serves as an editor for the IEEE Transactions on Wireless Communications, IEEE Transactions on Communications, IEEE Transactions on Mobile Computing, and IEEE Transactions on Information Forensics and Security.

T5 - Machine-type communications: form massive connectivity to ultra-reliable low latency communication

Speaker:

Hirley Alves
University of Oulu, Finland

Schedule

TBA

Summary

This tutorial focuses on Machine-type communications (MTC), from massive connectivity to ultra-reliability and low latency communications. MTC are at the core of the 5G revolution, which natively addresses MTC as: massive MTC and ultra-reliable, low latency communication. Massive MTC (mMTC) tackles issues related to large number of devices and their connectivity and spectral and energy efficiency. On the other hand, ultra-reliable, low latency communication (URLLC) focuses on mission critical communication where high reliability and low latency communication are mandatory. Thus enabling MTC networks operation with heterogeneous requirements -- massive connectivity, to ultra-reliability and low latency -- challenging current understanding of conventional techniques for wireless communications. In this tutorial we present common characteristics of distinct applications in different industry verticals (smart metering, V2X, industry automation), we discuss the current state-of-the-art, key challenges and open problems covering PHY, MAC and networking issues.

Biography

Hirley Alves received the B.Sc. and M.Sc. degrees from Federal University of Technology - Paraná (UTFPR), Brazil, in 2010 and 2011, respectively, both in Electrical Engineering. Hirley received dual D.Sc. degree from University of Oulu and UTFPR in 2015. Dr. Alves is Adjunct Professor on Machine-type Wireless Communications at Centre for Wireless Communications (CWC), University of Oulu, Oulu, Finland. Dr. Alves has acted as organizer, chair, and serves TPC to several renowned international conferences. Dr. Alves is engaged in several projects nationally and internationally (5GPPP) on mMTC and URLLC. Dr. Alves has given many tutorials on the topic of full-duplex communications for instance at European Wireless 2016, ISWCS’16 and 17, EUCNC’17, and the is the chair of the workshop series on full-duplex communications for future wireless networks at ICC’17, Globecom’17 and ICC’18. Dr. Alves has recently received the title of docent on Machine type Wireless Communications, and he is actively working on massive connectivity and ultra-reliable low latency communications. His research interests are wireless and cooperative communications, wireless full-duplex communications, PHY-security and ultra-reliable communications mechanisms for future machine type wireless networks.

T6 - Rate Splitting for MIMO Wireless Networks: A Promising PHY-Layer Strategy for 5G and Beyond

Speaker:

Bruno Clerckx,
Imperial College London, UK

Schedule

TBA

Summary

MIMO has grown beyond the original point-to-point channel and nowadays refers to a diverse range of centralized and distributed deployments. Numerous techniques have been developed in the last decade for MIMO wireless networks, including among others MU-MIMO, CoMP, Massive MIMO, NOMA, millimetre wave MIMO. All those techniques rely on two extreme interference management strategies, namely fully decode interference and treat interference as noise. Indeed, while NOMA based on superposition coding with successive interference cancellation relies on strong users to fully decode and cancel interference created by weaker users, MU-MIMO/Massive MIMO/CoMP/millimetre wave MIMO based on linear precoding rely on fully treating any multi-user interference as noise. In the presence of imperfect channel state information at the transmitter (CSIT), CSIT inaccuracy results in additional multi-user interference that is treated as noise by all those techniques.

In this tutorial, we depart from those two extremes of fully decode interference and treat interference as noise and introduce the audience to a more general and more powerful transmission framework based on Rate-Splitting (RS) that consists in decoding part of the interference and in treating the remaining part of the interference as noise. This capability of RS to partially decode interference and partially treat interference as noise enables to softly bridge and therefore reconcile the two extreme strategies of fully decode interference and treat interference as noise.

In order to partially decode interference and partially treat interference as noise, RS relies on the transmission of common (degraded) messages decoded by multiple users, and private (nondegraded) messages decoded by their corresponding users. As a result, RS pushes multiuser transmission away from conventional unicast-only transmission to superimposed unicast multicast transmission and leads to a more general class/framework of strategies. For instance, in a MISO Broadcast Channel, RS is shown to encompass NOMA and MU-MIMO with linear precoding as special cases. Through information and communication theoretic analysis, RS is shown to be optimal (from a Degrees-of-Freedom region perspective) in a number of scenarios and provide significant benefits in terms of spectral efficiencies, reliability and CSI feedback overhead reduction over conventional strategies used/envisioned in LTE-A/5G that rely on fully treat interference as noise or fully decode interference. The gains of RS will be demonstrated in a wide range of scenarios: multi-user MIMO, massive MIMO, multi-cell MIMO/CoMP, overloaded systems, NOMA, multigroup multicasting, mmwave communications, communications in the presence of RF impairments and coded caching. Signal processing and optimization techniques used to achieve the fundamentally promised gains are further presented and elaborated. Open problems and challenges will also be discussed.

Biography

Bruno Clerckx is a Reader (Associate Professor) in the Electrical and Electronic Engineering Department at Imperial College London (London, United Kingdom). He received his M.S. and Ph.D. degree in applied science from the Université catholique de Louvain (Louvain-la-Neuve, Belgium) in 2000 and 2005, respectively. From 2006 to 2011, he was with Samsung Electronics (Suwon, South Korea) where he actively contributed to 3GPP LTE/LTE-A and IEEE 802.16m and acted as the rapporteur for the 3GPP Coordinated Multi-Point (CoMP) Study Item. Since 2011, he has been with Imperial College London, first as a Lecturer (2011-2015), then as a Senior Lecturer (2015-2017), and now as a Reader. From March 2014 to March 2016, he also occupied an Associate Professor position at Korea University, Seoul, Korea. He also held visiting research appointments at Stanford University, EURECOM, National University of Singapore and The University of Hong Kong. He is the author of 2 books, 140 peer-reviewed international research papers, 150 standard contributions and the inventor of 75 issued or pending patents among which 15 have been adopted in the specifications of 4G (3GPP LTE/LTE-A and IEEE 802.16m) standards. Dr. Clerckx served as an editor for IEEE TRANSACTIONS ON COMMUNICATIONS from 2011- 2015 and is currently an editor for IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS. He is an Elected Member of the IEEE Signal Processing Society SPCOM Technical Committee. His research area is communication theory and signal processing for wireless networks.

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