2017 AusCTW
2017 Australian Communications Theory Workshop (AusCTW)

Australian National University — 18–20 January 2017

 Workshop Program

The Workshop will feature three keynote talks and a number of invited talks, poster sessions and all new 5-Minute Thesis Pitch Competition (5MTP). On Thursday, 19 January, the organizers will host a banquet for the Workshop attendees. Below is the Workshop program. Please check the program regularly for updates and possible changes.

Download the latest program in pdf format here

Keynote Talk 1: An information-theoretic perspective on interference management - Young-Han Kim - UCSD

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Abstract: For high data rates and massive connectivity, next-generation cellular networks are expected to deploy many small base stations. While such dense deployment provides the benefit of bringing radio closer to end users, it also increases the amount of interference from neighboring cells. Consequently, efficient and effective management of interference is expected to become one of the main challenges for high-spectral-efficiency, low-power, broad-coverage wireless communications.

In this talk, we introduce two competing paradigms of interference management and discuss recent developments in network information theory under these paradigms. In the first “distributed network” paradigm, the network consists of autonomous cells with minimal cooperation. We explore advanced channel coding techniques for the corresponding mathematical model of the “interference channel,” focusing mainly on the sliding-window superposition coding scheme that achieves the performance of simultaneous decoding through point-to-point channel codes and low-complexity decoding. In the second “centralized network” paradigm, the network is a group of neighboring cells connected via backhaul links. For uplink and downlink communications over this “two-hop relay network,” we develop dual coding schemes – noisy network coding and distributed decode-forward – that achieve capacity universally within a few bits per degree of freedom.

Speaker’s Bio: Young-Han Kim received his B.S. degree with honors in electrical engineering from Seoul National University, Korea, in 1996 and his M.S. degrees in electrical engineering and in statistics, and his Ph.D. degree in electrical engineering from Stanford University in 2001, 2006, and 2006, respectively. In 2006, he joined the University of California, San Diego, where he is currently an Associate Professor in the Department of Electrical and Computer Engineering. His research interests are in information theory, communication engineering, and data science. He coauthored the book Network Information Theory (Cambridge Press 2011). He is a recipient of the 2008 NSF Faculty Early Career Development (CAREER) Award, the 2009 US-Israel Binational Science Foundation Bergmann Memorial Award, the 2012 IEEE Information Theory Paper Award, and the 2015 IEEE Information Theory Society James L. Massey Research and Teaching Award for Young Scholars. He served as an Associate Editor of the IEEE Transactions on Information Theory and a Distinguished Lecturer for the IEEE Information Theory Society. He is a Fellow of the IEEE.

Keynote Talk 2: Massive MIMO with one-bit quantization, Lee Swindlehurst - UCI

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Abstract: The use of one-bit analog-to-digital (ADC) and digital-to-analog converters (DAC) has been proposed to reduce the otherwise overwhelming cost and energy consumption associated with massive MIMO communication systems, especially those that operate with very large bandwidths and thus very high sampling rates. This talk focuses on the issues associated with coarse quantization in massive MIMO systems, and demonstrates that the corresponding impact is minimal at low SNRs, and can be controlled through intelligent signal processing at low-to-medium SNRs. The Bussgang decomposition is used to show how to design appropriate linear decoders and precoders for the one-bit case, and to derive bounds on the resulting sum spectral efficiency of the system. Methods that exploit PSK signaling and the finite alphabet effect of one-bit DACs for the downlink are also presented to illustrate possible approaches. While a number of open problems remain, low-resolution quantization appears to be a promising approach to realizing massive MIMO systems with gigabit data rates.

Speaker’s Bio: A. Lee Swindlehurst received the B.S., summa cum laude, and M.S. degrees in Electrical Engineering from Brigham Young University, Provo, Utah, in 1985 and 1986, respectively, and the PhD degree in Electrical Engineering from Stanford University in 1991. From 1986-1990, he was employed at ESL, Inc., of Sunnyvale, CA, where he was involved in the design of algorithms and architectures for several radar and sonar signal processing systems. He was on the faculty of the Department of Electrical and Computer Engineering at Brigham Young University from 1990-2007, where he was a Full Professor and served as Department Chair from 2003-2006. During 1996-1997, he held a joint appointment as a visiting scholar at both Uppsala University, Uppsala, Sweden, and at the Royal Institute of Technology, Stockholm, Sweden. From 2006-07, he was on leave working as Vice President of Research for ArrayComm LLC in San Jose, California. He is currently Associate Dean for Research and Graduate Affairs in the Henry Samueli School of Engineering, and a Professor of Electrical Engineering and Computer Science at the University of California at Irvine. Dr. Swindlehurst is a Fellow of the IEEE and a Foreign Member of the Royal Swedish Academy of Engineering Sciences. He has served as Editor-in-Chief of the IEEE Journal of Selected Topics in Signal Processing, as a member of the Editorial Boards for the EURASIP Journal on Wireless Communications and Networking and the IEEE Signal Processing Magazine, and is a past Associate Editor for the IEEE Transactions on Signal Processing. He is a recipient of several paper awards: the 2000 IEEE W. R. G. Baker Prize Paper Award, the 2006 IEEE Signal Processing Society’s Best Paper Award, the 2006 IEEE Communications Society Stephen O. Rice Prize in the Field of Communication Theory and is co-author of a paper that received the IEEE Signal Processing Society Young Author Best Paper Award in 2001.

Keynote Talk 3: Error control coding and linear system security, Margreta Kuijper - University of Melbourne

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Abstract: This talk looks at feedback controlled systems. In recent years there have been several events where such systems have been cyber attacked, resulting in malfunctioning and damage. There is currently a need for an automated response as part of the resilience of the system. In this talk I will explore some of the fundamentals around linear closed-loop systems under cyber attack. More specifically, I will consider the scenario where a restricted number of system outputs is vulnerable to adversarial attacks that take place over time. I will introduce the fundamental notion of a system’s “security index” as an analogon of “minimal distance” in linear coding theory. Ideas from digital communications-linear coding theory can then be used for the purpose of attack detection and automated correction.

Speaker’s Bio: Margreta Kuijper is a Professor at the Department of Electrical and Electronic Engineering of the University of Melbourne (Australia) where she has been employed since 1995. From 1992 to 1995 she was a postdoctoral fellow at the Mathematics Department of the University of Groningen, the Netherlands. From 1988 to 1992 she worked at the Center of Mathematics and Computer Science (CWI), Amsterdam, where she obtained her PhD degree in 1992. Her main research interests evolve around the interplay between coding theory and systems theory. Current research interests include algebraic error control coding, erasure coding and cyber security of control systems. She served as an Associate Editor for SIAM Journal of Control and Optimization (2009 - 2013) and is currently on the editorial board of the International Journal of Information and Coding Theory (IJOCT; since 2014) as well as on the steering committee of the Symposium on the Mathematical Theory of Networks and Systems (MTNS; since 2006).

Talk 1: Design and Analysis on Transmit Beamforming for Millimetre Wave Cell Discovery, Stephen Hanly, Macquarie University

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Abstract: We develop an analytical framework for the initial access phase in a millimeter wave (mm-wave) communication system and propose an effective strategy for transmitting the reference signals used for BS discovery. Specifically, by formulating the problem of BS discovery at user equipments as hypothesis tests, we derive a detector based on Generalised Likelihood Ratio Test (GLRT) and characterise the statistical behaviour of the detector. Our theoretical results allow to analytically analyse the impact of key system parameters on the performance of BS discovery, and can guide to choose suitable system parameters for initial access. In particular, using the large deviation principle, we identify the asymptotically optimal beam patterns for RS transmission, which minimise the average miss-discovery probability of cell edge UEs.

Speaker’s Bio: Stephen Hanly (FIEEE) holds the CSIRO-Macquarie University Chair in Wireless Communications at Macquarie University, Sydney, Australia. He has been an Associate Editor for IEEE Transactions on Wireless Communications, Guest Editor for IEEE Journal on Selected Areas in Communications, and Guest Editor for the Eurasip Journal on Wireless Communications and Networking. In 2005 he was the technical co-chair for the IEEE International Symposium on Information Theory held in Adelaide, Australia, and he will be again, in 2017 in Aachen, Germany. He was a co-recipient of the best paper award at the IEEE Infocom 1998 conference, the 2001 Joint IEEE Communications Society and IEEE Information Theory Society best paper award, and the 2015 IEEE Communications Society best tutorial paper award.

Talk 2: Satellite-based Search & Rescue, Gottfried Lechner, UniSA

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Abstract: Satellite based Search & Rescue uses distress beacons transmitting a UHF signal when activated to allow detection and location. The original system uses a simple waveform and Low Earth Orbit (LEO) satellites exploiting primarily the Doppler Effect for localisation. Currently, a second generation of Search & Rescue systems is introduced using a spread spectrum signal and Medium Earth Orbit (MEO) satellites. This system allows for instantaneous detection and localisation with significantly higher accuracy. We present an overview of satellite based Search & Rescue, the waveforms used and results from field trials highlighting challenges in the detection of these signals.

Speaker’s Bio: Gottfried Lechner is Associate Research Professor in Telecommunications in the School of Information Technology and Mathematical Sciences at the University of South Australia. He is the Director of the Institute for Telecommunications Research where he leads a team of academic researchers, engineers and postgraduate students. Gottfried received his Dipl.-Ing. and Dr.techn. degrees from Vienna University of Technology, Austria, in 2003 and 2007, respectively. He worked as a software developer from 1999 to 2002 before joining the Telecommunications Research Centre Vienna in 2002 as a Researcher. In 2008 he joined the University of South Australia. Gottfried contributed to a number of funded research projects ranging from fundamental research to applied research and consulting. Current projects include one ARC Discovery Project, two ARC Linkage Projects and collaborative research projects with the Defence Science and Technology Group. Gottfried’s current research interests are in satellite communications and software defined radios.

Talk 3: Parallel Optimization Framework for Cloud-Based Small Cell Networks, Wibowo Hardjawana, University of Sydney

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Abstract: Cloud-based small cell networks (C-SCNs) have recently been proposed as new wireless cellular architecture. In cloud-based networks, optimization of radio resources at the base station (BS) is moved to a cloud data center for centralized optimization. In the center, multiple processors referred to as the cloud computational unit (CCU) are used for the optimization. As the cell size and networks become, respectively, smaller and denser, the number of BSs to be optimized grows exponentially, resulting in high computational complexity and latency at CCUs. In this paper, we propose belief propagation-based power allocation schemes for C-SCNs that can be used for any network optimization objectives, such as energy consumption minimization at the data center and BSs, and spectral efficiency. The computation for the schemes is distributed across multiple processors and done in parallel, leading to very low latency and computational complexity with increasing number of BSs. We will show that their performances in terms of spectral and energy efficiencies are close to an exhaustive search solution in finding the best configuration.

Speaker’s Bio: Wibowo received the Ph.D. degree in electrical engineering from The University of Sydney, Australia, in 2009. He is currently an Australian Research Council Discovery Early Career Research Award Fellow with the School of Electrical and Information Engineering, The University of Sydney. His current research interests are in wireless communications, with a focus on multiple-input-multiple-output, cloud, virtualisation, multiple access, cooperative communications, and coding techniques.

Talk 4: Leveraging Multiple Nano-Receivers for Reliable Molecular Communications, Nan Yang, Australian National University

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Abstract: Molecular communication (MC) has been acknowledged as one of the most promising nanoscale communication paradigms in bio-inspired nanonetworks, due to its unique potential benefits of bio- compatibility and low energy consumption. One of the primary challenges posed by diffusion-based MC is that its reliability rapidly decreases when the transmitter-receiver distance increases. One approach to enhancing its reliability is to use multiple receivers sharing common information to help transmission. In this presentation, I will introduce the new results on the error performance analysis achieved by collaborative detection among distributed nano-receivers in a diffusion-based MC system. Based on such analysis, I will also present the optimisation of the error performance. Numerical and simulation results reveal that the system error performance is greatly improved by combining the detection information of distributed nano-receivers

Speaker’s Bio: Nan Yang received his Ph.D. degree in communications and information systems from the Beijing Institute of Technology in 2011. He has been with the Research School of Engineering at the Australian National University since July 2014, where he currently works as a Future Engineering Research Leadership Fellow (Level C) and a Senior Lecturer. Over the past years, he received the IEEE ComSoc Asia-Pacific Outstanding Young Researcher Award, and the Exemplary Reviewer Awards from the IEEE Transactions on Communications, IEEE Transactions on Vehicular Technology, IEEE Wireless Communications Letters, and IEEE Communications Letters. Also, he is the co-recipient of Best Paper Awards at the IEEE GlobeCOM 2016 and the IEEE VTC Spring 2013. His general research interests include communications theory and signal processing, with specific interests in massive multiple-antenna systems, millimetre wave communications, collaborative and distributed signal processing, cyber-physical security, and molecular communications.

Talk 5: Information-Theoretic Security via Side Information, Lawrence Ong, University of Newcastle

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Abstract: Securing data communication channels is one of the key elements in safeguarding information, as most data in the digital world today are transmitted over the Internet. Using information theory, one can prove that certain protocols can secure communication channels such that eavesdroppers can obtain negligible information about the data being transmitted over the channels. Most existing information- theoretic security approaches require that eavesdroppers are crippled in some way, for example, having a noisier channel or having access to limited links. We investigate a novel approach to information-theoretic security using side information. Instead of relying on the eavesdroppers being crippled, this method leverages data cached at devices. In this talk, we will present a few recent results on security via side information.

Speaker’s Bio: Lawrence Ong received the BEng degree (1st Hons) in electrical engineering from the National University of Singapore (NUS), Singapore, in 2001. He subsequently received the MPhil degree from the University of Cambridge, UK, in 2004 and the PhD degree from NUS in 2008. Lawrence Ong was with MobileOne, Singapore, as a system engineer from 2001 to 2002. He was a research fellow at NUS, from 2007 to 2008. From 2008 to 2012, he was a postdoctoral researcher at The University of Newcastle, Australia. In 2012, Lawrence Ong was awarded a Discovery Early Career Researcher Award (DECRA) by the Australian Research Council (ARC); in 2014, he was awarded a Future Fellowship by the ARC. He is currently a Future Fellow at the University of Newcastle.

Talk 6: Analytical Handle for ZF Reception in Distributed Massive MIMO, Rajitha Senanayake, University of Melbourne

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Abstract: This work considers distributed massive MIMO networks where a large number of antennas, either collocated or geographically scattered over a region, communicate with mobile users. This communication is impaired by interference from similar transmissions in adjacent regions, the effect of imperfect channel state information and by noise. Focusing on zero-forcing (ZF) reception, we derive simple expressions that very accurately approximate the instantaneous signal-to-interference-plus-noise ratio (SINR) and the ergodic spectral efficiency of an arbitrary user within the network. These analytical expressions enable short-cutting any assessment of the network-level performance, either analytical or simulation-based.

Speaker’s Bio: Rajitha Senanayake is a Research Fellow at the University of Melbourne, Australia. She received her BSc degree in Electrical and Electronic Engineering from the University of Peradeniya and her Bachelor of Information Technology degree from the University of Colombo, Sri Lanka in 2009 and 2010 respectively. In December 2015, she received her PhD degree in Wireless Communications from the University of Melbourne. Soon after her PhD, she worked as a Research Fellow at the Department of Electrical and Computer Systems Engineering, at Monash University, Australia. She served as the finance chair for AusCTW and AusITS 2016. She was also the recipient of the best student paper award at AusCTW 2013. Her current research interests are in cooperative communications and user centric networks.

Talk 7: Buffer-Aided Relaying, Nikola Zlatanov, Monash University

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Abstract: The concept of buffer-aided relaying has recently emerged as a viable solution for improving the data rates and the outage probabilities of cooperative wireless networks. Buffer-aided relaying is a novel relaying concept, where relays use their buffers in order to relax the stringent reception-transmission constraints. In particular, in contrast to conventional relaying, where reception and transmission at relays has a predetermined schedule which is independent of the qualities of the receiving and transmitting channels, in buffer-aided relaying, the relays adaptively select to either receive, transmit, or simultaneously receive and transmit in a given time slot based on the qualities of the reception and transmission channels. Thereby, buffer-aided relaying always utilizes for transmission the stronger channels and, as a result, reduces the negative effects of fading. Buffer-aided relaying is a general concept which is applicable to all wireless networks with relays, where the relays can either be half-duplex or full-duplex. In this talk, we will introduce the concept of buffer-aided relaying and provide an overview of its applicability to a broad range of cooperative wireless networks.

Speaker’s Bio: Nikola Zlatanov was born in Macedonia. He received the Dipl.Ing. and Master degree in electrical engineering from Ss. Cyril and Methodius University, Skopje, Macedonia in 2007 and 2010, respectively, and his PhD degree from the University of British Columbia (UBC) in Vancouver, Canada in 2015. He is currently a Lecturer in the Department of Electrical and Computer Systems Engineering at Monash University in Melbourne, Australia. He received several scholarships/awards for his work, including UBC’s Four Year Doctoral Fellowship in 2010, UBC’s Killam Doctoral Scholarship and Macedonia’s Young Scientist of the Year in 2011, the Vanier Canada Graduate Scholarship in 2012, best journal paper award from the German Information Technology Society (ITG) in 2014, and best conference paper award at ICNC in 2016. He serves as an Editor of IEEE Communications Letters. He has been a TPC member of various conferences, including Globecom, ICC, VTC, ISWCS, etc. His current research interests include wireless communications, information theory, and nanonetworks.

Talk 8: Network Coding for Data Storage and Caching, Neda Aboutorab, The University of New South Wales, ADFA

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Abstract: In this talk, we introduce a conflict free instantly decodable network coding (IDNC) solution for file download from distributed storage servers. Considering previously downloaded files at the clients from these servers as side information, IDNC can speed up the current download process. However, transmission conflicts can occur since multiple servers can simultaneously send IDNC combinations of files to the same client, which can tune to only one of them at a time. To avoid such conflicts and design more efficient coded download patterns, we propose a dual conflict IDNC graph model, which extends the conventional IDNC graph model in order to guarantee conflict free server transmissions to each of the clients. We then formulate the download time minimization problem as a stochastic shortest path problem whose action space is defined by the independent sets of this new graph. Given the intractability of the solution, we design a channel-aware heuristic algorithm and show that it achieves a considerable reduction in the file download time, compared to applying the conventional IDNC approach separately at each of the servers.

Speaker’s Bio: Neda Aboutorab received the B.Eng. and M.Eng. degrees in electrical engineering from Iran University of Science and Technology and Amirkabir University of Technology, Tehran, Iran, in 2005 and 2008, respectively, and the Ph.D. degree in electrical engineering from the University of Sydney in 2012. From 2012-2015 she was a Postdoctoral Research Fellow at the Research School of Engineering, the Australian National University. In 2015 she joined in the School of Engineering and IT, University of New South Wales, Canberra, as a lecturer. Her research interests include network coding, wireless communications, data storage systems, compressive sensing, and signal processing.

Talk 9: High-Speed Aerial Backbones for Air-Space-Ground Integrated Information Networks, Xiaojing Huang, UTS

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Abstract: Air-space-ground integrated communication and networking is one of the most important targets of global research and development efforts. High-speed aerial backbones are the key components of such space information networks since they interconnect the space borne, airborne and ground based transmission platforms to form a seamless communications system. Currently, there have been some significant advances in space borne based communications networks. Ground based networks are also becoming more and more mature. However, the airborne based communications network is still in its early stage, for which how to achieve high-speed aerial backbone links is the most important task. This presentation gives a brief overview of current state-of-the-art in airborne based backbone technologies, and discusses how to realise high-speed transmission for air-to-air links and air-to-ground links from a high- altitude aerial platform using millimetre wave technologies. Research directions for achieving low cost and high flexibility aerial backbones using unmanned aerial vehicles are also suggested.

Speaker’s Bio: Xiaojing Huang received his Ph.D. degree in electronic engineering from Shanghai Jiao Tong University in 1989. With over 27 years of combined industrial, academic, and scientific research experience, he has authored over 240 book chapters, refereed journal and conference papers, and major commercial research reports, and filed 29 patents. He is currently a Professor of Information and Communications Technology with the School of Computing and Communications and the Program Leader of Mobile Sensing and Communications with the Global Big Data Technologies Centre, University of Technology Sydney (UTS), Australia. Before joining UTS, he had been a Principal Research Scientist at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia, and the Project Leader of the CSIRO Microwave and mm-Wave Backhaul Projects since 2009, an Associate Professor at the University of Wollongong, Australia, since 2004, and a Principal Research Engineer at the Motorola Australian Research Centre since 1998. He is a recipient of the CSIRO Chairman’s Medal and the Australian Engineering Innovation Award in 2012 for exceptional research achievements in multi-gigabit wireless communications.

Talk 10: Multiplexing in Quantum Communications, Robert Malaney, The University of New South Wales

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Abstract: This tutorial type presentation discusses some recent results and ideas related to improving the capacity of wireless links through the use of novel multiplexing techniques in the quantum domain. A particular focus will be on the use of Orbital Angular Momentum (OAM) and its relationship to line-of-sight MIMO techniques.

Speaker’s Bio: Robert Malaney received the Ph.D. degree in physics from the University of St Andrews, U.K. He held research positions with Caltech, National Labs with UC Berkeley, and the University of Toronto. He is currently an Associate Professor with the School of Electrical Engineering and Telecommunications, The University of New South Wales, Australia. He is a former Principal Research Scientist with CSIRO. He has authored over 150 publications.

Talk 11: Secrecy Performance of Cooperative Relay Systems with Transmit Antenna Selection and Unreliable Backhaul, Phee Lep Yeoh, University of Sydney

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Abstract: We examine the secrecy performance of a decode-and-forward cooperative relay system with multiple transmitters connected to a central unit over unreliable backhaul links. We derive the secrecy outage probability of transmit antenna selection in the presence of a passive eavesdropper with cyclic- prefixed single-carrier (CP-SC) transmissions and non-identical frequency selective fading between the relay and destination nodes. Asymptotic limits on the secrecy outage probability is derived for reliable and unreliable backhaul scenarios. Interestingly, we show that the asymptotic limit for unreliable backhaul is exclusively determined by the backhaul reliability parameter. This means that the diversity gain promised by CP-SC systems cannot be achieved with unreliable backhaul links. Simulations are presented to verify the derived impact of backhaul reliability on the secrecy performance.

Speaker’s Bio: Phee Lep Yeoh received the BE degree with University Medal in 2004 and the PhD degree in 2012 from the University of Sydney. His career has spanned academia, research and industry with previous roles at the University of Melbourne, CSIRO, and Telstra. In October 2016, he joined the University of Sydney as a Senior Lecturer at the School of Electrical and Information Engineering. He is a recipient of the 2014 ARC Discovery Early Career Researcher Award, IEEE ICC 2014 best paper award, IEEE VTC-Spring 2013 best paper award, and AusCTW 2013 best student paper award. He has served as a workshop organizer for VTC- Spring 2017, TPC chair for AusCTW 2016, and TPC member for IEEE GLOBECOM, ICC, and VTC conferences. His research interests include wireless physical-layer security, heterogeneous wireless networks, cooperative cognitive radio systems, and multiscale communication systems.

Talk 12: The Road to 5G Wireless Systems: Resource Allocation for NOMA, Derrick Ng, The University of New South Wales

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Abstract: The fifth-generation (5G) communication system is on its way. It is widely believed that 5G systems will provide new services and functionalities, such as internet-of-things (IoT), cloud-based architectural applications, etc. These envisioned services pose challenging requirements for 5G wireless communication systems, such as much higher data rates (100-1000 times of current 4G technology), lower latency (1 ms for a roundtrip latency), massive connectivity and support of diverse quality of service (QoS). It is expected that non-orthogonal multiple access (NOMA) will play a key role to unlock the potential of 5G due to its high spectral efficiency and user fairness. In particular, compared to conventional orthogonal multiple access (OMA), NOMA transmission allows multiple users to share the same frequency resource via exploiting the power domain multiplexing. In this talk, we will discuss various resource allocation problems in NOMA and the potential solutions.

Speaker’s Bio: Derrick Wing Kwan Ng received the bachelor degree with first class honors and the Master of Philosophy (M.Phil.) degree in electronic engineering from the Hong Kong University of Science and Technology (HKUST) in 2006 and 2008, respectively. He received his Ph.D. degree from the University of British Columbia (UBC) in 2012. He is now working as an assistant professor at the University of New South Wales, Sydney, Australia. Dr. Ng has published more than 90 journal and conference papers. He received the Best Paper Awards at the IEEE International Conference on Computing, Networking, and Communications 2016, the IEEE WCNC 2012, the IEEE Globecom 2011, and the IEEE Third International Conference on Communications and Networking in China 2008. Dr. Ng is currently an Editor of the IEEE Communications Letters, the IEEE Transactions on Wireless Communications, and the IEEE Transactions on Green Communications and Networking.

Talk 13: The Two-Modular Fourier Transform, Yi Hong, Monash University

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Abstract: In this talk we provide a solution to the open problem of computing the Fourier transform of a binary function defined over n-bit vectors taking m-bit vector values. In particular, we introduce the two- modular Fourier transform (TMFT) of a binary function f:G–>{R}, where G = (F_2^n,+) is the group of n bit vectors with bitwise modulo two addition +, and { R} is a finite commutative ring of characteristic 2. Using the specific group structure of G and a sequence of nested subgroups of G, we define the fast TMFT and its inverse. Since the image {R} of the binary functions is a ring, we can define the convolution between two functions (i.e., multiplication in the group ring {R}[G]). We then show the TMFT can be used to efficiently compute such convolution.

Speaker’s Bio: Dr Yi Hong received her Ph.D. degree in Electrical Engineering and Telecommunications from the University of New South Wales (UNSW), Sydney, Australia. She is currently a Senior Lecturer at the Department of Electrical and Computer Systems Eng., at Monash University, Clayton, Australia. She is a Senior Member of IEEE, a member of Communication Theory and Information Theory societies. She was the General co-Chair of 2014 IEEE Information Theory Workshop at Hobart, Tasmania; the Technical Program Committee Chair of the 2011 Australian Communication Theory workshop, Melbourne; and the Publicity Chair of 2009 IEEE Information Theory Workshop at Taromina, Sicily. She received the NICTA-ACoRN Early Career Researcher award at AUSCTW Adelaide 2007. Her research interests include communication theory and coding and decoding techniques for wireless communications and networking.

Talk 14: Non-Orthogonal Multiple Access with Practical Finite-alphabet Inputs, He Chen, University of Sydney

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Abstract: Recently, non-orthogonal multiple access (NOMA) has been regarded as one of the key enabling technologies to meet the unprecedented requirements of fifth generation (5G) wireless networks. By exploiting the power domain to simultaneously serve multiple users in the same time/frequency/code resource blocks, NOMA has demonstrated a great potential to support massive connectivity, achieve low latency, improve spectral efficiency, and enhance user fairness. The majority of recent studies on NOMA have relied on the assumption of Gaussian inputs. Although these designs with Gaussian signaling can achieve the capacity region, their direct applications in practical communication systems may lead to significant performance loss. This is due to the fact that practical wireless systems normally use finite constellation sets (e.g., phase shift keying modulation or quadrature amplitude modulation). This talk will first introduce the basic concepts and standardization progress of NOMA. Then, our recent work on the optimal design of NOMA with practical finite-alphabet inputs will be presented.

Speaker’s Bio: He (Henry) CHEN received his Ph.D. degree in electrical engineering from the University of Sydney in September 2015. He is currently a Research Fellow at the School of Electrical and Information Engineering, University of Sydney. He was a recipient of the International Postgraduate Research Scholarship (IPRS), the Australian Postgraduate Award (APA), and the Chinese Government Award for Outstanding Self-Financed Students Abroad. He was a Guest Editor of the 2016 special issue of millimeter wave wireless communications and networks in MDPI Sensors, and an organizer and Co-Chair of GLOBECOM 2016 workshop on wireless energy harvesting communication networks. He has been serving as a Regular Reviewer for more than 10 prestigious IEEE journals as well as the TPC members of several IEEE flagship conferences, such as GLOBECOM and ICC. He has co-authored more than 50 research papers in prestigious journals and conferences. His current research interests include millimeter wave wireless communications, non-orthogonal multiple access, wireless energy harvesting and transfer, cooperative and relay networks.

Talk 15: Achieving Reliable Cellular and Smart Grid Communication through Optimum Energy Sharing among Renewable Powered BSs, Shama Islam, Deakin University

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Abstract: With the enormous increase in cellular traffic now-a-days, more and more base stations (BSs) are being deployed to maintain the quality of service, especially, in metropolitan areas with densely located cellular users. Operation of a large number of BSs will imply large fuel cost and increase the operational expenditure. In this respect, renewable powered BSs can reduce the fuel usage by harnessing freely available energy like solar or wind energy, which leads to reduced expenditure on fuels. These renewable powered base stations (BSs) are equipped with battery energy storage systems (BESSs) and diesel generators for back-up supply. Due to the intermittent (random) nature of renewable energy, as well as the random nature of cellular traffic, these BSs may have energy surplus/deficit in a certain instant. As a result, these BSs engage in energy cooperation among themselves to match the overall energy generation and consumption with a focus to minimize the usage of diesel generator, while maintaining the required quality of service (QoS) at the cellular users. This energy cooperation is monitored and controlled by a control unit, which performs optimization operation based on the energy consumption and generation information transmitted by the BSs. Thus, the effectiveness of the energy cooperation (both in terms of reducing diesel usage and maintaining the QoS at the cellular users) critically depends on the reliability of information exchange between the BSs and the control centre. In this respect, we consider a joint optimization problem to find the optimum precoding vectors at the BSs and the control unit which minimize the usage of diesel fuel, as well as the mean square error (MSE) at the control unit and at the BSs, while maintain the required QoS at the cellular users. For the designed precoders, the error performances at the BSs, control unit and the cellular users, have been analyzed. Also, the impact of incorrectly received data at the control unit/ the BSs on energy cost reduction has been investigated. Finally, the effectiveness of energy cooperation under different realistic scenarios has been demonstrated through numerical simulations.

Speaker’s Bio: Shama Naz Islam received the PhD degree in Engineering from the Australian National University (ANU), Canberra, Australia in May, 2015. In March 2016, she joined the School of Engineering at Deakin University as a lecturer. Her research interests involve efficient and reliable transmission protocol design for smart grid communication. She has 16 publications in prestigious journals and peer-reviewed conferences, including IEEE Transactions on Vehicular Technology, IEEE Journal of Communications and Networks and IEEE Wireless Communications Letters. In 2012, she received the best student paper award in Women in Engineering category in IEEE Australia Council student paper contest. In 2014, she has been accredited as an associate fellow of the Higher Education Academy, UK.

Poster Session 1

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1- Graph-Theoretic Approaches to Two-Sender Index Coding

Authors: Chandra Thapa, Lawrence Ong, and Sarah J. Johnson

Institutions: The University of Newcastle

Abstract: Consider a communication scenario over a noiseless channel where a sender is required to broadcast messages to multiple receivers, each having side information about some messages. In this scenario, the sender can leverage the receivers’ side information during the encoding of messages in order to reduce the required transmissions. This type of encoding is called index coding. In this paper, we study index coding with two cooperative senders, each with some subset of messages, and multiple receivers, each requesting one unique message. The index coding in this setup is called two-sender unicast index coding (TSUIC). The main aim of TSUIC is to minimize the total number of transmissions required by the two senders. Based on graph-theoretic approaches, we prove that TSUIC is equivalent to single-sender unicast index coding (SSUIC) for some special cases. Moreover, we extend the existing schemes for SSUIC, viz., the cycle-cover scheme, the clique-cover scheme, and the local-chromatic scheme to the corresponding schemes for TSUIC.

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2- Reliability-Based Windowed Decoding for Spatially-Coupled LDPC Codes

Authors: Peng Kang, Yixuan Xie, Lei Yang, and Jinhong Yuan

Institutions: The University of New South Wales

Abstract: In this work, we propose an improved sliding window decoder and two reliability-based windowed decoding algorithms for spatially-coupled low-density parity-check codes. In the proposed sliding window decoder, we only reserve the high reliable messages generated in previous decoding window for the current decoding window. This reduces the effect of error propagation on sliding window decoding process and improves the error performance. The two reliability-based windowed decoding algorithms are devised from the conventional weighted bit-flipping (WBF) algorithm to achieve a low computational complexity. We first improve the flipping metric of the WBF algorithm for windowed decoding when multiple bits are allowed to be flipped in each iteration. This is achieved by combining the reliability from two adjacent iterations. We then enhance the flipping rule for windowed decoding that flips a carefully chosen single bit in each iteration. We evaluate the bit error rate performance of the proposed decoder and algorithms by using different window sizes. Simulation results show that the proposed windowed multi-bit WBF algorithm significantly lowers the error floor of the conventional WBF, whereas the performance of windowed single- bit WBF algorithm shows less than 0.05 dB gap from the performance of flooding schedule decoding.

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3- Joint Beamforming and Power Allocation Design in Downlink Non-Orthogonal Multiple Access Systems

Authors: Xiaofang Sun*#, Chao Shen*, Yanqing Xu*, Suhaib M. Al-Basit^, Zhiguo Ding^, Nan Yang#, and Zhangdui Zhong*

Institutions: *Beijing Jiaotong University, #The Australian National University, and ^Lancaster University

Abstract: We propose a joint design of beamforming and power allocation in a downlink multiple-input multiple-output multiuser system which employs non-orthogonal multiple access (NOMA). We address a new scenario where the users are divided into two groups by their quality of service (QoS) requirements, rather than the location information, such that the users in Group 1 expect to be served with the best efforts whereas the users in Group 2 require to reach target rates. For this scenario, the aim is to maximize the sum rate of the users in Group 1 while guarantee the minimum rates of the users in Group 2. We first apply the semidefinite relaxation (SDR) approach to linearize the quadratic forms of beamforming vectors, and then successively approximate the nonconvex constraints based on the arithmetic geometric mean inequality to jointly design the beamforming matrices and power allocation. Finally, we show that the proposed algorithm achieves a profound sum rate advantage over the existing ones, and examine the impact of parameters on the convergence rate of the proposed algorithm.

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4- Secret Pilot-Aided Channel Training and Power Allocation in Full-Duplex Wiretap Channels

Authors: Shihao Yan*, Xiangyun Zhou*, Nan Yang*, Thushara D. Abhayapala*, and A. Lee Swindlehurst#

Institutions: *The Australia National University and #University of California, Irvine

Abstract: This work proposes a new channel training (CT) scheme for a full-duplex receiver to enhance physical layer security. Equipped with NB full-duplex antennas, the receiver simultaneously receives the information signal and transmits artificial noise (AN). In order to reduce the non-cancellable self- interference due to the transmitted AN, the receiver has to estimate the self-interference channel prior to the data communication phase. In the proposed CT scheme, the receiver transmits a limited number of pilot symbols which are known only to itself. Such a secret CT scheme prevents the eavesdropper from estimating the jamming channel from the receiver to the eavesdropper, hence effectively degrades the eavesdropping capability. Compared with the traditional CT scheme that uses publicly known pilots, the newly proposed secret CT scheme offers significantly better performance when the number of antennas at the eavesdropper is larger than one, e.g., NE > 1. We analytically examine the connection probability (i.e., the probability of the data being successfully decoded by the receiver) of the legitimate channel and the secrecy outage probability due to eavesdropping for the proposed secret CT scheme. Based on the probability analysis, the optimal power allocation between CT and data/AN transmission at the legitimate transmitter/receiver is determined.

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5- Access Class Barring for M2M Communication under Data Aggregation and Trunking

Authors: Jason Lee, Jing Guo and Salman Durrani

Institutions: The Australian National University

Abstract: For machine-to-machine (M2M) communication, massive connection among low data rate machines introduces huge congestion and collision in the network system. Consequently, this reduces the system throughput during the reservation phase. Access class barring (ACB) scheme is proposed as a practical and effective congestion control mechanism. Thus, this work presents a generalized model that incorporates the idea of ACB scheme into the aggregation and trunking framework. Two different ACB schemes, i.e., fixed and dynamic ACB schemes are considered under one-shot transmission system to adapt the varying arrival of machine packets. Furthermore, a closed-form expression for sub-optimal and optimal ACB probability factors p is derived from the performance metrics to optimize the system performance. The system model is evaluated on machine served quantity, transmit power consumption, outage probability and collision probability. The results demonstrated that the fixed and dynamic ACB schemes exhibit overall better performance compared to the baseline model. Moreover, the results also showed that the fixed ACB scheme outperforms dynamic ACB since no extra time is required to update and broadcast the probability factor p. Nevertheless, dynamic ACB scheme has the potential to achieve the best performance among all models if the extra time is neglected.

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6- On the Design of Multi-dimensional Irregular Repeat-accumulate Lattice Codes

Authors: Min Qiu, Lei Yang and Jinhong Yuan

Institutions: The University of New South Wales

Abstract: We propose and design the lattice codes with finite dimensional constellations based on multi-dimensional lattice partition. The codes are constructed from non-binary irregular repeat-accumulate (IRA) codes. Most notably, we propose a novel encoding structure to ensure that the codes exhibit permutation-invariance and symmetry properties. With these two properties, the densities of the messages in our iterative decoder can be well modeled by Gaussian distributions described by a single parameter. Under the Gaussian approximation, extrinsic information transfer (EXIT) charts for our multi-dimensional IRA lattice codes are developed and used for analysing the convergence behaviour and optimising the decoding threshold. Simulation results show that our proposed lattice coding schemes outperform the previous designed lattice coding scheme with two-dimensional lattice partition.

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7- Millimeter Wave MIMO Channel Estimation Using Matrix Completion

Authors: Rui Hu, Jun Tong and Jiangtao Xi

Institutions: University of Wollongong

Abstract: Massive MIMO with hybrid transceiver architectures has attracted significant interests for millimeter wave (mmWave) communications. Channel estimation plays a critical role for optimizing the system performance. The existing studies on mmWave channel estimation have focused on compressive sensing (CS)-based schemes. This work studies an alternative approach based on matrix completion (MC), which leverages the low-rank nature of mmWave MIMO channels. The analysis and simulation results show that the MC-based estimator can lead to comparable capacities at a much lower complexity than CS-based schemes and is more robust against array uncertainties. The proposed approach can be applied to both switch-based and phase shifter-based hybrid MIMO architectures.

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8- Millimeter Wave Propagation Measurements and Channel Models for Fifth Generation Mobile Communication in Urban Macro Areas

Authors: Saurav Dahal, Jasmin Proud, Nick Hodson, Horace King, Mike Faulkner and Shabbir Ahmed

Institutions: Victoria University

Abstract: The fifth generation of mobile systems (5G) is due for commercialization by 2020 and will operate in the spectrum bands up to 86 GHz. This includes the millimeter wave bands, operating above 24 GHz. Millimeter waves enable an order of magnitude increase in bandwidth greater than 1 GHz, but are subject to higher attenuation due to rain, atmospheric effects and building penetration. The expected use cases for millimeter wave communications is based around hotspots where high capacity is required over a small area. Therefore, propagation environments such as urban microcells, picocells and indoor cells have been heavily studied [1-5]. Less work has been done for large cells with base station antennas above roof-top height. This poster describes urban macro measurements at 27 GHz conducted in the Footscray business area and within the Victoria University campus using an in-house developed wideband channel sounder having a 10 ns (3m) resolution. Key features of the poster include:

  1. The design of the equipment based on National Instrument USRP hardware to generate the intermediate frequency (IF) and up/down converters to get 27 GHz.

  2. Angle of Arrival (AOA) measurement hardware to identify scattering clusters.

  3. Early results comparing measured path loss to the current ITU model.

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9- Coverage Analysis of Packet Multi-Tier Networks with Asynchronous Slots

Authors: Vahid Naghshin, Mark C. Reed, and Neda Aboutorab

Institutions: The University of New South Wales, Australian Defence Force Academy

Abstract: Using stochastic geometry, the downlink (DL) and uplink (UL) coverage probabilities are derived for co-channel packet multi-tier heterogeneous cellular networks (HCN). The spatial locations of base stations (BSs) as well as user equipments (UEs) are modeled as independent spatial homogeneous Poisson point processes (PPP). The decoupled association is evaluated where the UE may connect to different BSs in the UL and DL transmissions. Unlike most of the existing work, the packet transmission slots are not synchronized, that is, the starting and ending points of the slots are not aligned. We investigate fundamental performance metrics of dynamic packet HCN for two traffic models, namely, the Slotted-Asynchronous and Exponential-Interarrival. Furthermore, tight lower bounds for the DL and UL coverage probabilities for two traffic models are obtained. The derived bounds are tight especially in high data rate regimes. The analysis provided herein enables us to determine the performance limits of packet-based HCNs with possible asynchronous time-slots. Simulation results are conducted to verify the analytical derivations. Furthermore, the performance comparison between pure synchronous and asynchronous packet-based systems is provided. The results confirm that the synchronous case outperforms the asynchronous one in terms of the UL and DL coverage probabilities at the cost of higher computational complexity.

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10- Optimal Energy Harvesting Parameters for a Single-hop DF Relay, with an Infinite Battery

Authors: Bhathiya Pilanawithana, Saman Atapattu, Jamie Evans

Institutions: The University of Melbourne

Abstract: Energy harvesting relay network is a promising method to extend the coverage of a wireless network without additional power requirement at the relay node. Shortcomings introduced due to the time varying nature of the channel can be made less severe by equipping the relay with energy and data buffers. We first introduce a model that can be widely applicable to many real world energy harvesting relay network scenarios. We then give a semi-analytical solution to optimal power-splitting energy harvesting at relay and optimal power allocations at source and relay. The semi-analytical solution is used to interpret the optimal behaviour of the system. We also propose an interior-point algorithm to numerically solve a finite channel case.

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11- Realistic Diffusion Channel in Molecular Communication

Authors: Trang Ngoc Cao*, Phee Lep Yeoh#*, Nikola Zlatanov^, and Jamie Evans*

Institutions: *The University of Melbourne, #The University of Sydney, and ^Monash University

Abstract: For wide applications of molecular communication, in which the diffusion channel cannot be modelled by Brownian motion, we consider anomalous diffusion model. Anomalous diffusion models the general and practical molecular propagation. Firstly, we use the fractional diffusion equation and derive the distribution of first passage time in terms of Fox’s H-function. We then analyze the bit error rate for timing and amplitude binary modulation schemes in anomalous diffusion.

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12- Joint Optimization of Downlink Full-Duplex Backhaul and Radio Access Network in Ultra-Dense Heterogeneous Networks

Authors: Xiangyue Meng*, Phee Lep Yeoh#*, Brian Krongold*

Institutions: *The University of Melbourne and #The University of Sydney

Abstract: In this work, we consider a joint downlink backhaul (BH) and radio access network (RAN) resource (power and subcarriers) allocation problem in ultra-dense heterogeneous networks. In our model, there is one macro base station (MBS) that transmits BH signals, and one small-cell base station (SBS) that serves all users. Furthermore, the SBS operates in full-duplex (FD) mode, where it receives and transmits signals from BH and to users on the same subcarrier at the same time. Our goal is to jointly optimize the resource allocation at the MBS and SBS in order to maximise the total user satisfaction in the network. Unfortunately, this problem is nonconvex and non-deterministic polynomial (NP) hard. Therefore we propose an algorithm that finds sub-optimal solutions via successive convex approximation (SCA) technique, which sequentially convexifies the non-convex constraints and solves the non-convex optimization problem by solving a sequence of convex subproblems. The sub-optimal solution can be found efficiently under the standard convex optimization framework. We present numerical simulations that verify the performance of the algorithm and the comparison with the half-duplex case is left for further work.

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13- Uncoordinated NOMA with Finite Blocklengths

Authors: Rana Abbas, Mahyar Shirvanimoghaddam, Yonghui Li and Branka Vucetic

Institutions: The University of Sydney

Abstract: Many grant-free non-orthogonal multiple access (NOMA) schemes have been recently proposed to solve the massive access problem of M2M communications. However, little has been done on characterizing the achievable bounds for such systems. In this work, we take a step forward in this direction. We consider an uncoordinated NOMA scheme where devices choose pilot sequences from a predetermined set as their signature. They jointly transmit it with their data and simultaneously with the rest of their devices. The receiver performs joint decoding to recover all the data. For this, we derive the expression for the system throughput in the finite blocklength regime. We investigate the average system performance with and without CSI. We consider both joint decoding and successive interference cancellation at the receiver side. Finally, we investigate the trade-offs between the data rate, transmit power and the number of active devices to maximize the system throughput.

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14- Cognitive Radio Enabled Vehicular Ad Hoc Networks

Authors: Rajith Abeywardana, Prof. Kevin Sowerby, Dr. Stevan Berber

Institutions: The University of Auckland

Abstract: Vehicular Ad hoc Network is an integral component of future Intelligent Transportation Systems that enables vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. Moreover, vehicular communication is an essential element of autonomous vehicles, in an era where self-driving cars are on the brink of reality. Satisfying the demands of data throughputs of these vehicular communication networks will be a daunting task. This research presents a solution to fulfil the data throughput requirements of vehicular communication applications such as safety, navigation, information, and entertainment through the use of Cognitive Radios.

Poster Session 2

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1- Demodulation of Reaction Shift Keying Signals in Molecular Communication with Complex Receiver Circuits

Authors: Hamdan Awan and Chun Tung Chou

Institutions: The University of New South Wales

Abstract: In recent years there is an increasing interest in understanding and engineering the communication in biological systems from information theory point of view. Motivated by this we design a diffusion-based molecular communication system where the transmitter uses Reaction Shift Keying (RSK) as the modulation scheme. We focus on the demodulation of RSK signal at the receiver. The receiver consists of a front-end molecular circuit and a back-end demodulator. The front-end molecular circuit is a set of chemical reactions consisting of multiple chemical species. The optimal demodulator computes the posteriori probability of the transmitted symbols given the history of the observation. The derivation of the optimal demodulator requires the solution to a specific Bayesian filtering problem. The key contribution of this paper is to present a general solution to this Bayesian filtering problem which can be applied to any molecular circuit and any choice of observed species. In this work we apply this solution of Bayesian filtering problem for two complex receiver circuits, i.e., protein kinase receiver circuit and 4-stage receiver circuit. Both these circuits use multiple intermediate chemical species involved in a number of reactions. Moreover, in this work we measure a pair of chemical species instead of individual number of species we measured in our previous work. We found that by carefully choosing the pair of chemical species to measure we can minimize error rate without measuring all chemical species.

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2- Superimposed Signalling Inspired Channel Estimation in Full-Duplex Systems

Authors: Abbas Koohian*, Hani Mehrpouyan#, Ali A. Nasir^, Salman Durrani*, Mohammad Azarbad^^, Steven D. Blostein^^^

Institutions: *The Australian National University, #Boise State University, ^King Fahd University of Petroleum and Minerals, ^^Shahid Chamran University, and ^^^Queens University

Abstract: Residual self-interference (SI) cancellation in the digital baseband is an important problem in full-duplex (FD) communication systems. In this work, by investigating the blind channel estimation in FD communication, we establish the condition for ambiguity free channel estimation. We then use this condition to propose a novel technique to simultaneously estimate the self-interference and communication channels. The novelty of this work lies on the proposed bandwidth efficient channel estimation techniques, which not only does it save bandwidth but it is also more power efficient compared to pilot-based channel estimations. The simulation results show that the proposed technique outperforms the pilot-based channel estimation method both in terms of MSE of channel estimation error and bit error rate.

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3- Multiuser Precoding and Channel Estimation for Hybrid Millimeter Wave Systems

Authors: Lou Zhao, Derrick Wing Kwan Ng, and Jinhong Yuan

Institutions: The University of New South Wales

Abstract: In this paper, we develop a low-complexity channel estimation method for hybrid millimeter wave (mmWave) systems, where the number of radio frequency (RF) chains is much less than the number of antennas equipped at each transceiver. Based on the estimated CSI, zero-forcing (ZF) precoding is adopted for multiuser downlink transmission. In addition, we derive a tight achievable rate upper bound of the system. Our analytical and simulation results show that the proposed scheme offer a considerable achievable rate gain compared to fully digital systems, where the number of RF chains equipped at each transceiver is equal to the number of antennas. Furthermore, the achievable rate performance gap between the considered hybrid mmWave systems and the fully digital system is characterized, which provides useful system design insights.

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4- A Novel Detection Algorithm for Random Multiple Access Based on Physical-Layer Network Coding

Authors: Zhuo Sun*, Lei Yang*, Jinhong Yuan*, and Marco Chiani#

Institutions: *The University of New South Wales and #University of Bologna

Abstract: In this paper, we propose a novel detection algorithm for random multiple access, which combines slot based decoding and frame based decoding to recover users’ messages. For the slot based decoding, we exploit a linear physical-layer network coding (LPNC) algorithm to decode the linear combinations of collided packets at each slot. By designing the coefficient matrix of linear combinations, we have the decoded linear combinations independent of each other in each slot. At frame level, we have equations constructed by linear combinations from all slots within one frame, and we adopt Gaussian elimination aided successive interference cancellation (GE-SIC) decoding method to recover users’ messages. We show that our LPNC algorithm can increase the number of linear combinations per slot by minimizing the decoding error probability. In addition, we demonstrate that the proposed scheme can significantly improve the system performance in terms of throughput and packet loss rate.

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5- The Capacity Region of the MIMO Broadcast Channel with Side Information in the High-SNR Regime

Authors: Behzad Asadi, Lawrence Ong, and Sarah J. Johnson

Institutions: The University of Newcastle

Abstract: We consider the Gaussian multiple-input multiple-output (MIMO) broadcast channel with an arbitrary number of antennas at each node where each receiver may a priori know some of the messages requested by other receivers as side information. We investigate the degrees-of-freedom (DoF) region of the channel which characterizes the capacity region in the high signal-to-noise ratio regime. We derive tight inner and outer bounds on the DoF region of the three-receiver channel, thereby establishing the DoF region. To derive the inner bound, we utilize interference alignment, zero forcing, time sharing, and two-symbol extension. To derive the outer bound, we construct enhanced versions of the channel, and upper bound their DoF region. In the case where all the nodes have the same number of antennas, we also draw an analogy between the DoF region, and the capacity region of the index coding problem.

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6- Full-Duplex Backscatter Interference Networks Based on Time-Hopping Spread Spectrum

Authors: Wanchun Liu*, Kaibin Huang#, Xiangyun Zhou*, and Salman Durrani*

Institutions: *The Australian National University and #The University of Hong Kong

Abstract: Future Internet-of-Things (IoT) is expected to wirelessly connect billions of low-complexity devices. For wireless information transfer (WIT) in IoT, high density of IoT devices and their ad hoc communication result in strong interference which acts as a bottleneck on WIT. Furthermore, battery replacement for the massive number of IoT devices is difficult if not infeasible, making wireless energy transfer (WET) desirable. This motivates: (i) the design of full-duplex WIT to reduce latency and enable efficient spectrum utilization, and (ii) the implementation of passive IoT devices using backscatter antennas that enable WET from one device (reader) to another (tag). However, the resultant increase in the density of simultaneous links exacerbates the interference issue. The issue is addressed in this poster by proposing the design of full-duplex backscatter communication (BackCom) networks where a novel multiple-access scheme based on time-hopping spread-spectrum (TH-SS) is designed to enable both one-way WET and two-way WIT in coexisting backscatter reader-tag links. Performance analysis of a two-link BackCom network is presented, including forward/backward bit-error rates and WET outage probabilities. Several interesting design insights are obtained, such as: the performance tradeoff between the backward IT and the forward IT/ET w.r.t. the reflection coefficients, the performance tradeoff between the forward IT and ET w.r.t. the TH-SS sequence length.

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7- A New Outer Bound for Distributed Index Coding Sum Rates

Authors: Yucheng Liu*, Parastoo Sadeghi*, Young-Han Kim#, Fatemeh Arbabjolfaei#

Institutions: *The Australian National University and #University of California, San Diego

Abstract: After being introduced in 1998, index coding has received significant research interest and has been explored intensely in the past decades. Various coding schemes and bounding techniques have been developed and used to achieve various inner and outer bounds, yet the capacity region of general index coding problem remains open. Different from the traditional and well-studied centralized index coding problem, distributed index coding with multiple servers has only been studied in a few works before, with even more unanswered questions. In this poster, a new outer bound for the sum rates of general distributed index coding problem is proposed. It is then applied to all four-user cases to obtain results tighter than what can be achieved from previous works.

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8- Self-Coherent OFDM with Undersampling Down-Conversion for Wireless Communications

Authors: Qianyu Jin, Yi Hong

Institutions: Monash University

Abstract: In this paper, we introduce self-coherent orthogonal frequency-division multiplexing (OFDM), a well-known non-coherent technique in optical communications, for wireless radio frequency (RF) communications. Self-coherent OFDM provides complete immunity against phase noise (PN) using a non-coherent receiver and a significantly higher spectral efficiency than self-heterodyne (self-het) OFDM, which utilizes at most 50% of the available spectrum for communications. We present the performance analysis of self-coherent OFDM over additive white Gaussian noise (AWGN) and frequency selective fading channels, and show by simulations that self-coherent OFDM provides both higher spectral efficiency and better bit error rate (BER) performance than self-het OFDM. Considering that filter realization in high frequency bands is challenging, we adopt a undersampling down-conversion technique in conjunction with self-coherent OFDM. We show that with the self-coherent demodulation, the additional PN introduced by undersampling down-conversion can be significantly reduced. We compare analytically the system performance of self-coherent OFDM using undersampling downconversion with two other conventional OFDM systems: one with super-heterodyne receiver and the other with undersampling down-conversion. We show theoretically and by simulations that both in AWGN and frequency selective fading channels, self-coherent OFDM with undersampling down-conversion outperforms the two conventional OFDM systems even when intercarrier interference (ICI) compensation schemes are applied.

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9- Trellis Coded Modulation for Informed Receivers

Authors: Xuepeng Xiao, Yi Hong, Emanuele Viterbo, and Anindya Gupta

Institutions: Monash University

Abstract: We study coding schemes for the case where a source wishes to communicate several messages to multiple informed receivers over a noisy broadcast channel. Compared with the conventional coding problem, the informed receivers demand all the messages of the source but has known the exact values of some of these messages prior to the transmission as side information. We propose a trellis coded modulation (TCM) based scheme, called TCM for informed receivers (TCMIR) for this scenario to exploit the side information at each informed receiver to minimize the bit error rate. All messages are jointly encoded using this scheme and only one encoded message is transmitted. Each informed receiver can recover all messages via decoding the transmitted message and their unknown messages are decoded more reliably compared to a receiver with no side information. In this coded modulation scheme, the encoder is the concatenation of a selector and a rate k / (k+1) convolutional encoder. Every k+1 coded bits are mapped to a signal point from a 2^{k+1} constellation. We propose new bit labeling rules to guarantee that the performance gain of any informed receiver is independent of the actual value of the side information. Good TCMIR schemes are found by code search which is based on the analysis of free Euclidean distance. The representative patterns of knowing different messages are also discussed to reduce the complexity of code search. Bit error rate of TCMIR is compared with coding schemes available in the literature.

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10- The First 5G Mobile System 24 GHz Millimetre Wave Propagation Measurements in a Rural Macro Scenario

Authors: Shabbir Ahmed, Saurav Dahal, Mike Faulkner and Horace King

Institutions: Victoria University

Abstract: The 3rd Generation Partnership Project (3GPP) standardization body for 5G mobile systems is considering millimetre wave frequencies in the underutilised 24.25 GHz to 27.5 GHz and 37 GHz to 43.5 GHz bands among others. 3GPP has recently adopted new channel models for frequencies greater than 6 GHz [1]. The poster presents the first millimetre wave propagation measurements in a rural macro (RMa) deployment scenario [2]. We used sporting grounds, parks and gardens to emulate a rural environment. The measurements showed reasonable agreement with 3GPP’s original RMa model. 3GPP has used this as evidence to extend the validity of the RMa model from 6 GHz up to 30 GHz [3]. Further analysis shows foliage can cause significant attenuation. Additional losses of 20 dB are reported for an avenue of trees. Scattering off high objects is a key propagation mode into heavily shadowed non-line-of-sight areas, and can enable coverage to over 1 km from modest base station heights.

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11- The Influence of User Distribution Variability in Sectorized Cellular Network on Throughput Performance

Authors: Nadhiya L. M. Kamal, Kevin W. Sowerby, Michael J. Neve

Institutions: The University of Auckland

Abstract: A surge in mobile data traffic has driven network providers to increase the capacity of a wireless network. Capacity is proportional to the available bandwidth and SINR. However, bandwidth is a scarce resource hence solutions to increase capacity revolve around methods to increase bandwidth efficiency and improve SINR. Many resource allocation utilizing OFDM have been developed to improve bandwidth efficiency, therefore increasing the throughput of the network. Through resource allocation, transmission of data takes into account the channel condition of the users in the network. Most study in sectorized cellular network assumes equal probability distribution of users and equal bandwidth allocation in each sector of the cell. In reality, user distribution in each sector of the cell may differ hence varying the throughput performance. The research work carried here involves investigating the effects of varying user distribution on throughput performance for a single cell (sectorized) in downlink OFDM network. Traffic model has been developed to compute the throughput performance for a cell containing sectors with high user distribution near the base station, near the cell edge or a mix of both. Results have shown that throughput is lower in a sector with smaller SINR distribution. The variation in user distribution is exploited by allocating more bandwidth to the sector with smaller SINR distribution. This has resulted in a more just throughput performance across the sectorized cell and able to increase the overall throughput performance for a given throughput threshold.

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12: Cross-Layer Optimized Routing Across Multiple Wireless Body Area Networks (BANs)

Authors: Samiya Shimly*#, David B. Smith*#, and Samaneh Movassaghi*#

Institutions: *CSIRO Data 61 and #The Australian National University

Abstract: In this paper, we study the performance of two cross-layer optimized dynamic routing techniques for radio interference mitigation across multiple coexisting wireless body area networks (BANs), based on real-life experimental measurements. At the network layer, the best possible route is selected according to channel state information from the physical layer, associated with low duty cycle TDMA at the MAC layer. The routing techniques (i.e., shortest path routing (SPR), and novel cooperative multi-path routing (CMR) incorporating 3-branch selection combining) perform real-time and reliable data transfer across BANs operating near the 2.4 GHz ISM band. An open-access experimental dataset of `everyday’ mixed-activities is used for analyzing the proposed cross-layer optimization over the wireless body-to-body communications (BBN). We show that CMR gains up to 13 dB improvement with 8.3% TDMA duty cycle, and even 10 dB improvement with 0.2% TDMA duty cycle over SPR, at 10% outage probability at a realistic signal-to-interference-plus-noise ratio (SINR). Acceptable packet delivery ratios (PDR) and spectral efficiencies are obtained from SPR and CMR with reasonably sensitive receivers across a range of TDMA low-duty cycles, with up to 9 dB improvement of CMR over SPR at 90% PDR. The distribution fits for received SINR through routing are also derived and validated with theoretical analysis. The received outcomes ratify the expediency of the proposed cross-layer strategies to be effectively implemented in pervasive real-world applications with large-scale and highly connected healthcare systems comprising many closely-located BANs.

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13: Network-Coded Base Station Offloading in Device Fog Networks

Authors: Kameliya Kaneva, Neda Aboutorab, Mark Reed

Institutions: The University of New South Wales, Australian Defence Force Academy

Abstract: The Device Fog Architecture (DFA) was introduced with the aim to make use of the shorter, faster and cheaper links between devices so that the access to the base station (BS) can be minimized. The clients can cooperatively exchange data and employ network coding in order to help each other to retrieve their missing packets. Here, we assume that the network is fully connected and discuss the problem of offloading the BS in half duplex scenarios using instantly decodable network coded (IDNC) transmissions. Our ultimate target is to minimize the number of orthogonal channels needed from the BS to serve the requests that are not cooperatively served by the clients. We use the traditional IDNC graph but since the problem is NP hard, we implement the Backward Induction Algorithm (BIA) which helps us to analyse the problem and understand necessary conditions of the optimal solution. We will use this knowledge to create a heuristic algorithm suitable for real-time implementations.

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14: Optimal Co-Phasing Power Allocation for Coordinated OFDM Transmission

Authors: Bing Luo*, Phee Lep Yeoh#*, Brian Krongold*

Institutions: *The University of Melbourne and #The University of Sydney

Abstract: We consider an orthogonal frequency division multiplexing (OFDM) coordinated transmission system in which K coordinated transmission points (CTPs) coherently transmit and allocate power across N subchannels under individual power constraints. In maximizing the system capacity, we derive a novel co-phasing power allocation solution with an interesting property: For any subchannel, if the power allocation of one CTP is zero, then the power allocation of all the other CTPs must be zero. Otherwise, the non-zero power allocation of all CTPs must follow a particular proportional rule which establishes the connection of optimal power allocation for all subchannels among all CTPs. This property also shows that the optimal power allocation is quite different from classical waterfilling and maximum ratio transmission (MRT), as more power is not necessarily allocated to the subchannels with better channel conditions. Based on this property and derived solution, we successfully reduced the constrained optimization problem with NK variables into an unconstrained one with only K variables, which simplifies computation significantly. Numerical results are presented to verify our theoretical findings.

Poster Session 3

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1- Predistortion for nonlinear satellite channels

Authors: Kelvin Layton, Azam Mehboob, William Cowley, and Gottfried Lechner

Institutions: University of South Australia

Abstract: In modern communication satellites, the transmit signal is distorted due to a nonlinear power amplifier and linear channel filter, leading to a degradation in performance. This work proposes a pragmatic predistortion technique to compensate for these distortions on-board the satellite. The predistorter uses a Wiener model consisting of a linear and nonlinear component to separately compensate for the channel filter and power amplifier. The Wiener model contains an FIR filter and a memoryless polynomial, trained using regularised least squares. An extensive simulation framework was used to compare the performance of various algorithms and included realistic models of a travelling-wave tube amplifier and channel filter. Additionally, hardware testing was performed on a low-power solid- state amplifier using high-speed DAC and ADC cards. A 64-ASPK modulation scheme was tested at a symbol rate of 500Msym/s. The Wiener predistorter reduces the total degradation by approximately 3dB compared to a system with no compensation, demonstrating the effectiveness of the proposed strategy.

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2- Analysis and design of Raptor codes using a multi-edge framework

Authors: Sachini Jayasooriya, Mahyar Shirvanimoghaddam, Lawrence Ong, and Sarah J. Johnson

Institutions: The University of Newcastle

Abstract: Raptor codes are a class of graph-based codes, which have been inspired by the idea of rateless coding. A Raptor code is a concatenation of a Luby transform (LT) code with an outer code, which is usually a high rate LDPC code. Although Raptor code design has been well investigated for different binary input channels, there has been little progress on universal design methods for the binary-input additive white Gaussian noise (BI-AWGN) channel, and a complete analysis, especially for the asymptotic performance of Raptor codes, is still missing. This motivates us to propose a more general design framework for Raptor codes using a multi-edge framework. In this regard, we first represent the Raptor code as a multi-edge type low-density parity-check (MET-LDPC) code. This MET representation gives a more general framework to analyze and design Raptor codes over a BI-AWGN channel using MET density evolution (MET-DE). The advantage of using MET-DE over conventional Gaussian approximation-based approaches, such as mean-LLR-EXIT chart, is that MET-DE does not incorporate any Gaussian approximation, thus MET-DE enables to find the optimal Raptor code for a given channel condition. We then consider two decoding schemes based on belief propagation (BP) decoding, namely tandem decoding and joint decoding in the multi-edge framework, and analyze the convergence behavior of the BP decoder using MET-DE. In tandem decoding, the inner LT code is decoded first and soft information is then sent to the precoder, whereas in joint decoding, both inner LT code and precode are decoded in parallel and soft information is exchanged between the decoders. We then propose a more efficient Raptor code design method using the multi-edge framework, where we simultaneously optimize over the inner LT code and the precoder. Finally, we extend the analysis to design higher-order modulated Raptor codes using the multi-edge framework. Through density evolution analysis we show that the designed Raptor codes using the multi-edge framework outperform the existing Raptor codes in literature in terms of the realized rate.

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3- A Distributed, Incrementally Deployable MIMO Wireless Network

Authors: Gerard Borg

Institutions: The Australian National University

Abstract: This study presents a simple analysis of a distributed and incrementally deployable, massive MIMO network. This network may exploit an existing back-haul customer access network such as FTTP to exchange side-information for MIMO beam-forming and for data sharing. The network is rolled out opportunistically as remote clients come on- line. Such a network can be deployed in a cell-free manner making it ideally suitable for community-operated wireless access when cellular mobile access is unavailable. We use a HATA model to compare the performance of this approach to a conventional cellular network of massive MIMO base stations / femto cells deployed within the same range of coverage.

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4- Performance Analysis of a Hybrid Downlink-Uplink Cooperative NOMA Scheme

Authors: Zhiqiang Wei*, Linglong Dai#, Derrick Wing Kwan Ng*, and Jinhong Yuan*

Institutions: *The University of New South Wales and #Tsinghua University

Abstract: This paper proposes a novel hybrid downlink-uplink cooperative NOMA (HDU-CNOMA) scheme to achieve a better tradeoff between spectral efficiency and signal reception reliability than the conventional cooperative NOMA schemes. In particular, the proposed scheme enables the strong user to perform a cooperative transmission and an interference-free uplink transmission simultaneously during the cooperative phase, at the expense of a slightly decrease in signal reception reliability at the weak user. We analyze the outage probability, diversity order, and outage throughput of the proposed scheme. Simulation results not only confirm the accuracy of the developed analytical results, but also unveil the spectral efficiency gains achieved by the proposed scheme over a baseline cooperative NOMA scheme and a non-cooperative NOMA scheme.

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5- Characterization of Aggregate Received Power from Power Beacons in Millimeter Wave Ad Hoc Networks

Authors: Xiaohui Zhou, Salman Durrani and Jing Guo

Institutions: The Australian National University

Abstract: Wireless power transfer (WPT) has emerged as an attractive solution to power future wireless communication networks. In this paper, we consider WPT using power beacons (PBs) for a millimeter wave (mmWave) wireless ad hoc network. Using stochastic geometry, we derive the moment generating function (MGF) and the nth cumulant of the aggregate received power from PBs at a reference receiver in closed-form. The MGF allows the complementary cumulative distribution function (CCDF) of the aggregate received power from PBs to be numerically evaluated. We also compare different closed-form distributions which can be used to approximate the CCDF of the aggregate received power. Our results show that the lognormal distribution provides the best CCDF approximation compared to other distributions considered in the literature. The results also show that under practical setups, it is feasible to power users in an mmWave ad hoc network using PBs.

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6- Turbo Compressed Sensing Using Message Passing De-Quantization

Authors: Amin Movahed, Mark C. Reed and Neda Aboutorab

Institutions: The University of New South Wales, Australian Defence Force Academy

Abstract: A new technique to concatenate 1-bit compressed sensing with a convolutional channel encoder for transmission of sparse signals over a memoryless AWGN channel is introduced. At the reconstruction part, an iterative decoder, referred to as turbo-CS decoder, is proposed. At the turbo-CS decoder, the sparse signal is decoded through iterations between an a posteriori probability decoder and a soft-in/ soft-out 1-bit compressed sensing decoder. By numerical experiments, we show that the turbo-CS decoder outperforms the state-of-the-art algorithms for 1-bit compressed sensing reconstruction in the presence of AWGN channel by more than 10 dB in terms of signal reconstruction performance.

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7- Interference Prediction in Wireless Networks with Mobile Nodes Governed by General Mobilities

Authors: Yirui Cong, Xiangyun Zhou, and Rodney A. Kennedy

Institutions: The Australian National University

Abstract: In a wireless network with mobile nodes (e.g., UAV communications), effective prediction of time-varying interferences can enable adaptive transmission designs and therefore improve the communication performance. This poster investigates interference prediction in wireless networks with a finite number of nodes by proposing and using a general-order linear model for node mobility. The proposed mobility model can well approximate node dynamics of practical wireless networks, e.g., UAVs’ mobilities. In contrast to previous studies on interference statistics, we are able through this model to give the best estimate of the time-varying interference at any time rather than long-term average effects. Finally, our simulation results corroborate the effectiveness and accuracy of the analytical results on interference prediction and also show the advantages of our method in dealing with complex mobilities.

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8- Covert Communication under Channel Uncertainty

Authors: Khurram Shahzad, Xiangyun Zhou, and Shihao Yan

Institutions: The Australian National University

Abstract: Covert Communication is to achieve a reliable transmission from a transmitter to a receiver while guaranteeing an arbitrarily small probability of this transmission being detected by a warden. We consider a covert communication system under block fading channels, where users experience uncertainty about their channel knowledge. The transmitter seeks to hide the covert communication to a private user by exploiting a legitimate public communication link, while the warden tries to detect this covert communication by using a radiometer. We derive the exact expression for the radiometer’s optimal threshold, which determines the performance limit of the warden’s detector. Furthermore, for given transmission outage constraints, the achievable rates for legitimate and covert users are analysed, while maintaining a specific level of covertness. Our numerical results illustrate how the achievable performance is affected by the channel uncertainty and required level of covertness.

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9- Evaluation of Spatial Active Noise Cancellation Performance Using Spherical Harmonic Analysis

Authors: Hanchi Chen, Jihui (Aimee) Zhang, Prasanga N. Samarasinghe, Thushara D. Abhayapala

Institutions: The Australian National University

Abstract: We propose a novel method to evaluate the performance of spatial active noise cancellation (ANC) systems. The acoustic potential energy within a spherical region can be expressed by a weighed squared sum of spherical harmonic coefficients. Therefore there is no need to take multiple samplings of the control region, which simplifies the ANC performance evaluation. The proposed metric allows convenient evaluation of spatial ANC performance using a spherical microphone array. In order to evaluate the effectiveness of this metric, we set up an experimental ANC system and conducted a series narrow band and wide band ANC experiments. The results show that the proposed potential energy method provides a reliable characterization of the performance of spatial ANC systems.

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10- Maximum Likelihood Detection of Distributed Cooperative Multi-Receiver Molecular Communication

Authors: Yuting Fang*, Adam Noel#, Nan Yang*, and Andrew W. Eckford^

Institutions: *The Australian National University, #University of Ottawa, and ^York University

Abstract: Molecular communication (MC) has been acknowledged as one of the most promising nanoscale communication paradigms in bio-inspired nanonetworks, due to its unique potential benefits, such as bio- compatibility and low energy consumption. The simplest molecular propagation mechanism is free diffusion where the information-carrying particles propagate from the transmitter to the receiver via Brownian motion. One of the primary challenges posed by diffusion-based MC is that its reliability rapidly decreases when the transmitter-receiver distance increases. One approach to enhancing its reliability is to use multiple receivers sharing common information to help transmission. In our work, we design maximum likelihood detection in a diffusion-based distributed cooperative multi-receiver MC system. In our system, we assume that there are K receivers and each receiver make M observations. The receivers report their observations to a fusion centre (FC), and the FC uses ML detection to obtain a global decision on the transmitted bit. We investigate different ML detection variants, such as selecting the most probable transmitted bit to maximise the joint likelihood of KM observations. We consider the perfect reporting scenario in the symmetric topology. Simulation results demonstrate that the system error performance of different ML detection variants are greatly better than those of hard decision fusion rules and a simple soft fusion rule which we have considered before. Based on simulation results, we conclude that ML detection provides the lower bound on the error performance of cooperative MC system with any practical fusion scheme design.

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11- Biologically Inspired Self-Organization for Node-Level Interference Mitigation of Multiple Coexisting Wireless Body Area Networks

Authors: Samaneh Movassaghi*#, David B. Smith*#, and ^Mehran Abolhasan

Institutions: *CSIRO Data 61, #The Australian National University, and ^University of Technology, Sydney

Abstract: This work presents a node-level Self-organizing Interference Avoidance Scheme (SIAC) between multiple coexisting wireless body area networks (WBANs) that incorporates self-organization and smart spectrum allocation. It follows a biologically inspired approach based on the theory of pulse-coupled oscillators for self-organization. The proposed scheme makes three major contributions as compared to the current literature. Firstly, it considers node-level interference for internetwork interference mitigation rather than considering each WBAN as a whole. Secondly, it allocates synchronous and parallel transmission intervals for interference avoidance in an optimal manner and dynamically adapts to changes in their coexistence. Finally, it achieves collision-free, self-organized communication with only information of the firing signal of each WBAN and does not require a global coordinator to manage its communications. It operates on a nodes traffic priority, signal strength, and density of sensors in a WBAN. Simulation results show that our proposal achieves a fast convergence time despite the little information it receives. Moreover, SIAC is shown to be robust to variations in signal strength, number of coexisting WBANs and number of sensor nodes within each WBAN. It is shown to mitigate interference of each WBAN while increasing the network lifetime.

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12- Cyber-Physical System Security: Attack Detection and Correction Using Polynomial Approach

Authors: Zhanghan Tang and Margreta Kuijper

Institutions: The University of Melbourne

Abstract: Real-world attacks on the cyber-physical system have in fact occurred in the past decade and have some significant damage to the targeted system. In this study, the problem of attack detection and attack correction for the discrete-time linear cyber-physical system under sensor attack is considered. Using the concept of security index and polynomial approach, a class of MIMO residual generator can be designed. Under certain assumptions, the residual generators are guaranteed to detect which sensors are under adversary attack and able to correct the attacked sensor in a simple manner.

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13- Multi-Pattern Inter-Cell Interference Coordination for Users with Different Mobility in an Ultra-Dense HetNet

Authors: Hanning Gu*, Phee Lep Yeoh#*, Brian Krongold*

Institutions: *The University of Melbourne and #The University of Sydney

Abstract: Ultra-Dense Networks (UDNs) are one of the most important trends towards next generation cellar systems. Although the benefit of traffic offloading is significant, the overhead of frequent inter- and intra-tier handovers in a UDN may result in poor overall performance. A high-mobility user may end up with ping-pong handovers if the small cell density is too high, while on the other hand, low-mobility users are better off in a high-density network where handover overhead is not significant for them. This ongoing work is inspired by the idea of multi-pattern inter-cell interference coordination for stationary users, where in each pattern a different selection of base stations is turned on for the benefit of particular users, while others base stations are off to mitigate interference. Our aim is to find an optimal small-cell density corresponding to every user’s speed, so that users with higher speeds can be best served in a pattern with lower small-cell density and low mobility users are to be associated with a high-density pattern. This intuition has been verified by intensive simulations. To obtain some theoretical insight, we propose to start with a simple model with one small cell to investigate the impact of speed and cell size on the user’s throughput. We plan to add complexity to our model by considering more small base stations.

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14- Wireless Body Area Networks: Energy-Efficient, Provably Socially-Efficient, Transmit Power Control

Authors: Yizhou Yang*# and David B. Smith*#

Institutions: *CSIRO Data 61 and #The Australian National University Abstract: Transmit power control is vital to wireless body area networks (BANs), where due to their prevalence many BANs may be required to coexist reliably, with a requirement for reduced power consumption to significantly increase sensor battery lifetime. In this paper, we propose a socially optimal finite repeated non-cooperative transmit power control game, in order to mitigate radio interference amongst coexisting BANs, improve throughput and reduce power consumption. The game is shown to have a unique Nash equilibrium. We also prove that the outcome of the game is socially efficient, given reasonable constraints, across all players at the unique Nash equilibrium. Using a realistic channel model, the game is shown to be very energy-efficient, significantly reducing power consumption and improving packet delivery ratio (PDR) with respect to other potential schemes, consuming 67% less circuit power than transmitting constantly at 0 dBm.

5-Minute Thesis Pitch Competition

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  1. Samaneh Movassaghi, Data61, Interference Mitigation amongst Coexisting Wireless Body Area Networks.

  2. Yifei Huang, Australian National University, Load balancing and User Association for 5G Networks.

  3. Alice Bates, Australian National University, Sampling and Reconstruction of Signals on the Sphere.

  4. Behzad Asadi, University of Newcastle, Increasing the Wireless Network Capacity via Caching.

  5. Amin Movahed, The University of New South Wales, ADFA, Iterative Receiver Techniques for Source/Channel Decoding Using Compressed Sensing.