Agenda

See below for more information on the respective sessions and talks. 

Tuesday, November 21

Wednesday, November 22

Thursday, November 23

More information on the talks

Keynote 1: Sir John Brian Pendry on "Metamaterials open new horizons in electromagnetism"

In the last decade a new area of research has emerged as a result of our ability to produce materials with entirely novel electromagnetic properties. Known as metamaterials because they take us beyond the properties of conventional materials, they display remarkable effects not found in nature, such as negative refraction. Spurred on by these new opportunities, theorists have produced exotic concepts that exploit the new materials: we can now specify how to make a lens whose resolution is limited not by the laws of nature but only by our ability to build to the stated specifications; we can guide radiation along a trajectory, avoiding objects and causing them to appear invisible; we can design and manufacture materials that are active magnetically in the optical range. There has been a truly amazing amount of innovation but more is yet to come. The field of metamaterials is developing into a highly disruptive technology for a plethora of applications where control over light (or more generally electromagnetic radiation) is crucial, ­ amongst them telecommunications, solar energy harvesting, stealth, biological imaging and sensing, and medical diagnostics.

Keynote 2: Mathias Fink on "Shaping waves in complex media with tunable metasurfaces: From Acoustics to Electromagnetism"

Starting with demonstrations of “time-reversal mirrors” that use active antenna array made of multiple antenna (MU-MIMO communications) to focus in complex environment, I will discuss the way to replace these antennae by tunable metasurfaces to obtain the best communication performance. The main idea is to replace the transmitting antennas by a smart modification of the wireless environment by physically shaping the propagation medium to achieve optimal focusing and channel diversity. I will show how the optimization of these metasurfaces results from the generalization of the “time reversal mirror” concept to the one of the convolution products of different time-reversal mirrors associated with each transmitter and receiver. I will discuss these approaches in term of the number of spatio-temporal degrees of freedoms of a wavefield. I will describe these metasurfaces which today are called reconfigurable intelligent surfaces (RIS) both in the narrowband regime for electromagnetic communications and in the wideband regime for sound communications. I will show that, when dealing with audible sound waves, the problem is much more complex that for narrowband RIS, as the reconfigurable surface needs to cover a wide range of frequencies spanning several decades. This research opens the field of ultrawideband RIS communications systems.

Session 1: 

Cristian Della Giovampaola on "Digitally-controlled reconfigurable metasurfaces for 6G and beyond"

Future communication networks require real-time control of how radio waves radiate, reflect and scatter through the propagation medium. In recent years, metasurfaces, engineered bidimensional structures that are naturally prone to reconfigurability, have been proposed as a key component for the next communication systems as they could be employed both to design beam-scanning antennas and to implement reconfigurable metasurfaces in general.

The first types of reconfigurable antennas relied on phase array architectures, based on the use of power amplifiers and phase shifter, which require a considerable amount of power to steer the antenna beam. A new type of reconfigurability, suitable for greener, more power efficient and environment friendly devices, is based on the use of reconfigurable elements such as varactors, PIN diodes, transistors, switches, to name a few. These elements require a considerably lower amount of energy to perform their operation, when compared to a phased array configuration and can be integrated directly onto the metasurfaces. Their use can lead to power efficient beam-scanning antennas, as well as to quasi-passive Reconfigurable Intelligent Surfaces.

Despite the promising effects of this new type of electronic reconfigurability, the design of the devices that make use of this technology can be highly complex, if the number of reconfigurable elements is high and/or if the device needs to provide multiple functionalities. Therefore, designing such complex structures if often prohibitive when using commercial electromagnetic software. In this presentation, we will show the most recent achievements at Wave Up in the field of the modeling and the design of digitally-controlled reconfigurable metasurfaces that can implement functionalities suitable for both current and future communications systems, based on the integration of reconfigurable elements directly on the metasurface.

Marco Di Renzo on "Analysis and Optimization of Reconfigurable Intelligent Surfaces by Using Multiport Network Theory"

Multiport network theory is a suitable abstraction model for analyzing and optimizing reconfigurable intelligent surfaces (RISs), especially for studying the impact of the electromagnetic mutual coupling among radiating elements that are spaced less than half of the wavelength.
The representations in terms of Z-parameter (impedance) and S-parameter (scattering) matrices are widely utilized. In this talk, we elaborate on multiport network theory for analyzing and optimizing the reradiation properties of RIS-aided channels, with focus on four key aspects. (i) We offer a thorough comparison between the Z-parameter and S-parameter representations. This comparison allows us to unveil that typical scattering models utilized for RIS-aided channels ignore the structural scattering from the RIS, which results in an unwanted specular reflection. (ii) We develop an iterative algorithm for optimizing, in the presence of electromagnetic mutual coupling, the tunable loads of the RIS based on the S-parameters representation. We prove that small perturbations of the step size of the algorithm result in larger variations of the S-parameter matrix compared with the Z-parameter matrix, resulting in a faster convergence rate. (iii) We develop a new algorithm to suppress the specular reflection due to the structural scattering, while maximizing the received power towards the direction of interest, and analyze the effectiveness and tradeoffs of the proposed approach. (iv) Finally, we validate the theoretical findings and algorithms with numerical simulations and a commercial full-wave electromagnetic simulator based on the method of moments.

Angel Lozano on "MIMO and Intelligent Surfaces: A Marriage Made in Heaven"

We are in the midst of a tidal transformation in the conditions in which wireless systems operate, with a determined push towards higher frequencies (today mmWave, tomorrow sub-terahertz) and shorter transmission ranges. This is stretching, even breaking, time-honored modelling assumptions such as that of planar wavefronts. And, once that classic paradigm is transcended, the opportunity arises for spatial multiplexing even when no multipath components are present. Then, an intelligent surface can augment the number of spatial degrees of freedom even as the transmitter and receiver apertures remain fixed. This possibility, which is revealed only as the curved nature of the wavefronts is accounted for, results from the intelligent surface acting as a lens that enables resolving denser spatial multiplexings. This presentation posits that, besides the more obvious benefits of enhancing the received power and sidestepping blockages, the true potential of intelligent surfaces might lie in serving as environmental apertures: multipath propagation on steroids, controllable, and on-demand.

Session 2: 

Emilio Calvanese Strinati on "The post Shannon Era: Towards Semantic, Goal-Oriented and Reconfigurable Intelligent Environments aided 6G communications"

This talk promotes the idea that including semantic and goal-oriented aspects in future 6G networks can produce a significant leap forward in terms of system effectiveness and sustainability. Semantic communication goes beyond the common Shannon paradigm of guaranteeing the correct reception of each single transmitted packet, irrespective of the meaning conveyed by the packet. The idea is that, whenever communication occurs to convey meaning or to accomplish a goal, what really matters is the impact that the correct reception/interpretation of a packet is going to have on the goal accomplishment. Focusing on semantic and goal-oriented aspects and possibly combining them with the reconfigurable and intelligent wireless environments paradigm, help to identify the relevant information, i.e. the information strictly necessary to recover the meaning intended by the transmitter or to accomplish a goal. With this keynote, after a short presentation of most recent state of the art approaches, we present our most recent results and cover in detail challenges and opportunities associated with the evolution towards semantic, goal-oriented and reconfigurable intelligent environments aided 6G communications.

Christoph Studer on "Algorithms, Architectures, and Hardware Implementations for Beyond-5G MIMO Systems"

Massive multiple-input multiple-output (MIMO) is a core technology of beyond-5G multi-user mmWave/terahertz communication systems. While massive MIMO enables high spectral efficiency via fine-grain beamforming, naïve implementations of all-digital BS architectures would result in excessive system costs, power consumption, and interconnect data rates. The large bandwidths available at mmWave/terahertz frequencies exacerbate these problems even more. In this talk, we discuss recent progress on the algorithm, architecture, and hardware implementation levels towards high-throughput multiuser communication at low power. Concretely, we discuss the following topics: low-resolution baseband processing, resolution-adaptive architectures, and beamspace equalization.

Panel

Thomas Zemen on "Reliable and Green 6G Wireless Communications"

Reliable wireless communication links are a key technology for the digitization of the society and economy in areas such as transport, manufacturing, and health. The exponential annual growth of mobile data traffic requires radically new technologies for the sixths mobile communication generation (6G) in 2030. In 10 years wireless communication systems must enable a 10 fold growth of throughput while simultaneously reducing power consumption and latency compared to current 5G systems. To reach these goals we investigate sustainable 6G technologies focusing on reconfigurable intelligent surfaces and widely-distributed cell-free massive MIMO systems. For both 6G technologies we briefly explain the key ideas and show novel 6G proof of concepts (PoCs) available in the software defined radio lab at AIT in Vienna, Austria.

Klaus Witrisal on "The potential of sub-10GHz frequency bands for 6G"

It is argued that the sub-10 GHz bands may keep playing an important role in future 6G wireless networks, while up to THz frequency bands are being proposed to support the ever-increasing demand for bandwidth. Specifically, distributed massive-MIMO systems will offer not only an unprecedented communications performance in terms of throughput and low latency, but also sensing capabilities, positioning, and even wireless power transfer. The main challenge is seen in the practical implementation: Can the theoretical advantage in energy efficiency be leveraged in practice, when hundreds of transmit/receive signals have to be processed at extremely demanding levels of synchronization?

Christoph Mecklenbräuker on "Joint Communication and Sensing beyond Line-of-Sight"

This talk will be devoted to the necessity of cooperative sensing and reconfigurable intelligent surfaces for Joint Communications and Sensing at mm-Waves.

Mario Huemer on "Model based versus data driven signal processing for the physical layer"

I plan to give two short examples, namely model based versus data driven self-interference cancellation for mobile phone radio frequency transceivers working in frequency division duplex mode, and model based versus data driven versus hybrid data estimation approaches for some selected communication waveforms.

Andrea Tornello on "Generative AI for the design of the 6G air interface"

My talk will be spent explaining what generative AI is in the context of comms, if/when ML learning makes sense, the mathematics behind it, some specific examples of AI models for the air interface design and analysis.

Keynote 3: Björn Ekelund on "6G - Enabling the cyberphysical world" 

Wireless communications systems are a key driver for hardware and software technologies and lays the foundation for a digitalized and sustainable future in both industry and everyday life. The next generation wireless communications standard, 6G, is only a few years away and will offer completely new levels of automation, intelligence, and security. 6G will do many things, one of them being a bridge between our physical world and the digital one. Innovation in sensors, representation, and user interface technologies also will give rise to complete new use cases and concepts, of which some will be discussed in more detail.

Session 3:

Visa Koivunen on "Multicarrier ISAC: Waveforms, Signal Processing and Learning"

In ISAC sensing and communication systems cooperate and may even be co-designed for mutual benefit. ISAC is facilitated by parallel convergence of multi-function HW, RF circuitry, adaptive large aperture multi-antenna systems and fully adaptive multi-function radars. Most current and emerging wireless communications systems including 5G and 6G employ MC waveforms that provide high spectral efficiency and robust communication performance. The use of MC waveforms have been considered for passive and active radar applications as well. This talk focuses on waveform design and optimization, signal processing, adaptation and reinforcement learning for MC ISAC systems. Practical examples of high relevance will be provided on ensuring desired performance level for sensing and communications tasks, radar signal processing using MIMO-ODFM model and model-based reinforcement learning for resource allocation.

Andre Bourdoux on "Sensing with a Cell-free MIMO Infrastructure"

MIMO communications systems have been successfully standardized and deployed during the last two decades and have grown in sophistication. It is anticipated that their distributed form, dubbed cell-free MIMO (CF-MIMO), will be a key new technology in 6G networks. At the same time, the wireless community has become aware of the great sensing potential offered by communications equipment, whether the infrastructure or the user devices. Sensing is also expected to be a major new 6G feature.

In this talk, we will consider the use of a CF-MIMO infrastructure for sensing. Several topics will be presented: a communications-sensing multiplexing technique using the uplink, a method to reduce the tight sensing synchronization requirements of the CF-MIMO base stations or access points and a discussion on the resolution capabilities of a CF-MIMO topology, going beyond the bandwidth-dictated resolution.

Markku Juntti on "Integrated sensing and communications in cellular networks – wideband joint waveforms"

We discuss and summarize the architectural options for radar type sensing in cellular networks to enable integrated sensing and communications (ISAC) operations. The key characteristics of monostatic and multistatic radar operation are briefly reviewed and the design challenges for cellular ISAC are discussed. We focus then more closely to the design problem of downlink transmit beamforming at a base station serving multiple users and performing simultaneously monostatic target sensing. The waveform design principles are introduced for single and multiple targets. The implications of wideband multicarrier operation are described and the performance optimization in this regime is discussed. Both optimization-based algorithms and deep unfolding based data driven JCAS design are introduced. Finally, we discuss the timely research challenges in the area.

Session 4:

Andreas Müller on "The Do’s and Don’ts of 6G Development"

While 5G is rapidly becoming the dominant mobile technology around the world, it has yet to fully deliver on its initial promises, especially in vital sectors such as the mobility, manufacturing, or healthcare domains. Reflecting on recent years, there are certainly valid reasons for this, but in order to avoid making the same mistakes again, we should consider the lessons learned in the development of 6G right from the outset. This presentation summarizes some of the key aspects in this regard and at the same time highlights major 6G building blocks that hold significant potential, particularly in the so-called vertical industries. Finally, some concrete recommendations are given how to ensure that 6G for vertical industries eventually becomes a major success.

Meik Kottkamp on "On the verge to 6G – A Test & Measurement Perspective"

While 5G NR is further deployed and enhanced globally with an increasing number of networks and end users, academia and industry are exploring the next wireless technology, namely 6G. This presentation will provide an insight on the main research directions from a test and measurement perspective. It will reflect the anticipated timelines, discuss potential new spectrum bands applicable to 6G and illustrate some of the research projects, Rohde & Schwarz is actively contributing to.

Slawomir Stanczak on "The Road to 6G - Insights from the 6G Research Innovation Cluster (6G-RIC)"

In this talk, we discuss some of the challenges and advances on the road to 6G. In particular, the talk provides insights into the latest research results and trends from the perspective of the 6G Research Innovation Cluster (6G-RIC) in areas such as cell-free Massive MIMO (sub-6GHz and sub-THz communications), intelligent reflecting surfaces, and machine learning in the 6G air interface. The 6G-RIC is an ambitious and comprehensive interdisciplinary research program addressing the key technical challenges of 6G.