Special Sessions

SS1/ Special Session on: ” Terabits\Terahertz Communications”

Terahertz (THz) technologies, which are often referred as beyond-5G communication enablers by the scientific community, are today attracting a great interest from both academia and industry. This is due to the huge available bandwidths, from tens to hundreds of gigahertz, while the threat on the human health is likely to be minor. As the millimeter-wave communication systems are becoming mature, the focus of the research activities is naturally moving to the THz range. The continuous increase in wireless capacity and thus bandwidth requirements makes the D bands (110-170 GHz) and then H bands (220-330 GHz) a highly valuable investigation field to support future challenging communication traffic and applications. In particular, broad THz bandwidths can be used for terabit-per-second (Tb/s) short-range wireless communications, or ultra-high capacity backhaul.

Although the research community has stepped up its efforts in the recent years, by leveraging  state-of-the-art devices and channel propagation knowledge, the THz techniques are far from the maturity achieved in microwave, millimeter-wave, and photonics. The key issue is that THz wireless systems cannot be implemented with existing technology. First concern is the design of high-performance reasonable-cost devices that include powerful THz sources, high-gain antennas and sensitive THz detectors, which can overcome the strong physical attenuation suffered in free-space. Elaboration of integrated systems will be the key asset to reduce the energy consumption and cost while making the system more compact.

In addition to those hardware considerations, the characterization and modelling of the PHY-layer components, including the propagation channel (line-of-sight and obstructed line-of-sight propagation modes), RF performance/constraints and antennas, are of primary importance to assess and optimize the investigated THz communication systems. The PHY-layer testbed experimentations and the creation of appropriate models are hot topics that should provide the THz research community with essential knowledge and tools. Although THz technology is thought to satisfy future demand for ultra-high data rates and capacity, many technical challenges need to be overcome or better understood before starting wide-scale industrial developments.

The goal of this special session is to share the recent progress made in the emerging THz communication domain, relying on innovative transmission and detection techniques (based on optics/wireless or electronics), transceiver architectures, antenna design, models, scenarios, etc, paving the way towards the realization of first telecommunication links. Topics of interest include, but are not limited to:

  • Signal generation from photomixers,
  • Terahertz modulations and wave transmitters
  • Terahertz wave detectors/receivers
  • Antenna design
  • Hybrid beamforming
  • Terahertz wireless/optical communications and applications
  • Terahertz indoor communications
  • Advances on experimental hardware design and implementation
  • Advanced discrete-time signal processing techniques
  • Filters design and ultra-low resolution receivers
  • Terahertz propagation and channel modelling
  • System simulation

Organizers

Guillaume Ducournau, Univ. of lille-France, <guillaume.ducournau@iemn.univ-lille1.fr>
Yoann Corre, SIRADEL, France, < ycorre@siradel.com >
Ali Al Ghouwayel, Lebanese International Univ. LIU-Lebanon < ali.ghouwayel@liu.edu.lb >


SS2/ Special Session on:  “Non Orthogonal Multiple Access Techniques for 5G systems”

Aim and scope:

Next-generation (5G and beyond) radio access networks are expected to meet heterogeneous demands on massive connectivity, low latency, high reliability, and to ensure a flexible and efficient use of all available resources, such as spectrum and time. As a result, significant efforts have been recently made to design more spectrally and energy efficient multiple access schemes for future wireless networks. The key idea of non-orthogonal multiple access (NOMA) schemes is to serve several users in the same resource unit, such as time slot, frequency subband or spreading code. A downlink version of NOMA called multiuser superposition transmission (MUST) has been proposed for 3rd generation partnership project long-term evolution advanced (3GPP-LTE-A) networks and NOMA has become an important principle for the design of radio access techniques for the 5G networks.

We aim to bring together leading researchers in the field to share their recent findings on NOMA techniques. Topics of interest include, but are not limited to:

  • Power-domain NOMA, code-domain NOMA and related multiple access schemes
  • Performance analysis and simulation of NOMA systems
  • Resource allocation for NOMA systems
  • Channel coding and modulation of NOMA systems
  • MIMO techniques and beamforming with NOMA
  • Cooperative communication with NOMA
  • NOMA performance with limited or imperfect channel feedback
  • Physical layer security in NOMA systems
  • Cross-layer optimization for NOMA systems
  • Implementation issues in NOMA
  • Emerging applications of NOMA

Organizers

Catherine Douillard, IMT Atlantique, France <catherine.douillard@imt-atlantique.fr>
Charbel Abdel Nour, IMT Atlantique, France <charbel.abdelnour@imt-atlantique.fr>
Joumana Farah, Lebanese University, Lebanon <joumanafarah@ul.edu.lb >


SS3/ Special Session on: “Advances on Digital Pre-distortion and Crest Factor Reduction”

High spectral efficiency and high energy efficiency are two major concerns for modern radio-communication and broadcast systems. To achieve high data rates with good spectral efficiency, they use wide-bandwidth modulation waveforms with high crest factor or PAPR (Peak to Average Power Ratio). But the transmission of such signals with a good energy efficiency is very challenging since power amplifiers can be highly non-linear when they are operated to maximize their energy efficiency. The higher the PAPR, the more difficult it is to reach a good trade-off between linearity and energy efficiency. The necessary transmission quality makes it mandatory to correct this non-linear behavior to preserve the transmitted waveform and the quality of the associated services.

Digital pre-distortion (DPD) is a very efficient linearization technique that it is widely applied in cellular base stations in conjunction with crest factor reduction (CFR) methods. But DPD and CFR techniques are faced with many new challenges in 5G and beyond systems with carrier aggregation, multiple antennas, use of mmWaves, use of GaN Technology …

The aim of this special session is to bring together leading researchers in the field to share their recent findings on DPD and CFR techniques. Topics of interest include, but are not limited to:

    • Architectures, models of DPD and identification algorithms: DPD multi-stages, multi-dimensional DPD, low complexity for mobile …
    • Wide bandwidth signals: subband DPD, multi-band DPD, harmonic DPD …
    • DPD and new waveforms: 5G, carrier-aggregation, MIMO  …
    • DPD for optical links
    • DPD for mmWave transmitters
    • Sizing of DPD: orthogonal matching pursuit, genetic algorithm, hill climbing …
    • DPD and impact/mitigation of power amplifier output stages: filter, antenna …
    • Joint optimisation DPD / CFR
    • Joint DPD and frequency-dependent IQ modulator compensation

Organizers

Geneviève Baudoin, ESYCOM / ESIEE Paris, France <g.baudoin@esiee.fr>
Roman Marsalek, BUT Brno, Czech Republic <marsaler@feec.vutbr.cz>
Olivier Venard, ESYCOM / ESIEE Paris, France <o.venard@esiee.fr>