Scientific direction Development of key enabling technologies
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PhD : selection by topics

Technological challenges >> Communication networks, IOT, radiofrequencies and antennas
6 proposition(s).

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Autonomous network management solution for deterministic networks using Artificial Intelligence (AI) techniques

Département Intelligence Ambiante et Systèmes Interactifs (LIST)

Laboratoire Systèmes Communiquants

01-02-2021

SL-DRT-21-0178

siwar.benhadjsaid@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

The objective of the thesis is to explore and evaluate the gain that could bring the Artificial Intelligence (AI) techniques to the network management solutions for deterministic networks. The goal is to help deterministic networks to ensure the preservation of the quality of service (QoS) during the routing of end-to-end data flow no matter what changes are made to the network. This will allow to design an autonomous network management solution that is able to configure deterministic networks in the most appropriate way and adapt the configuration when needed (e.g. new terminal connecting to the network, unexpected high latency for certain critical flows, change of the topology caused by the reorganization / reconfiguration of components of the production chain in the factory etc.). This solution will use artificial intelligence methods to learn from experience the conditions that lead to non-compliance with application flow requirements (high latency, low bandwidth, etc.). Learning takes place to recognize, upstream, the situations that may lead to non-compliance with the constraints of application flows and also to predict the effects of changes in input data (new terminal, reorganization of the plant, etc.) on the level of QoS provided to flows in transit. Based on such knowledge, the solution will anticipate QoS degradation situations and, consequently, will decide and push the adequate network reconfiguration which will make it possible to respect the constraints associated with each application flow.

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Distributed resource allocation for meshed networks of mobile users in shared spectrum

Département Systèmes (LETI)

Laboratoire Sans fils Haut Débit

01-09-2021

SL-DRT-21-0186

mickael.maman@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

In future 5G wireless networks, it is imperative to easily deploy and manage a private network of mobile users such as a fleet of vehicles or UAVs. The objective of this thesis is to define a distributed resource allocation for mesh networks of mobile users in the shared spectrum through resource pooling (time/frequency) and efficient management of directional antenna beams. While existing studies focus on maximizing the performance of static backhaul multi-beam mesh networks, we are interested in collaborative local/distributed learning between mobile users. The first step of this thesis will be to integrate a realistic model of sub 6-GHz and/or mmW directional antennas in a network simulator. A trade off between the spatiality of the directivity, the antenna efficiency and the complexity of the algorithm will be made for point-to-point and point-to-multipoint communications. Moreover the antenna configurations will be contextualized between the communication, discovery or tracking phases. The second step of this thesis will concern the design of the distributed resource allocation protocol during different stages of the network life: deployment, self-optimization and self-healing. A trade-off will be made between the type and latency of antenna (re)configuration, the accuracy of beam alignment, the channel coherence time for mobile users (volatile connectivity) and the convergence time of the scheduling.

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Wideband mmW receiver architectures based on innovative modulation schemes

Département Systèmes (LETI)

Laboratoire Architectures Intégrées Radiofréquences

01-03-2021

SL-DRT-21-0216

joseluis.gonzalezjimenez@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

Existing telecommunication and data communication networks are evolving towards extremely high capacity and data-rate connections that will require innovative transceiver architectures. For wireless data links, beyond 5G and 6G and systems will be required in the next 5 to 10 years able to provide 100Gb/s or higher data rates by efficiently using the wide spectrum available at millimeter-wave (mmW) or sub-THz frequencies. Traditional transceiver architecture that have been used in the past may result too power consuming or simply not performant enough to respond to this challenge. The LETI research institute has been conducting research during the lasts year in the field of innovative modulations schemes and transceiver architectures trying to respond to the above-mentioned high data-rate in wireless environments considering the limitation imposed by existing electronic devices required to build the transceivers. This thesis subject will explore the practical implementation of circuits based on innovative modulation schemes and architectures for high-speed, large-bandwidth, imperfection resilient mmW receivers for beyond 5G and 6G telecommunication applications and other high data-rate wireless communications applications.

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Millimeter Wave Short Range RadCom

Département Systèmes (LETI)

Laboratoire Architectures Intégrées Radiofréquences

01-09-2021

SL-DRT-21-0258

cedric.dehos@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

Mmw transceiver chips for high data rate, short range communication should be integrated soon in most mobile devices as contacless connectors. The wide bandwidth of these mmw transceiver may be used for fine resolution proximity radar, gesture recognition, biometric identification or Human Machine Interface. The thesis will investigate the possibility of slightly modifying the RF transceiver architecture to get the double feature of radar and communication in the same low cost and low power chip. The non-coherent communication architecture may evolve towards IR-UWB or FM-CW radar, with impact on the receiver complexity and radar performance. The PHD will evaluate the different alternatives, considering integrated low power radar processing and Artificial Intelligence embedded in MCU for analysis and classification.

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Optomechanical reference oscillators

Département Composants Silicium (LETI)

Laboratoire Composants Micro-Capteurs

01-09-2021

SL-DRT-21-0351

marc.sansaperna@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

Reference ocillators (clocks) are devices that generate signals with a very precise frequency, generally defined by the vibration of a mechanical element at resonance. Nowadays, they are ubiquitous elements in electronic circuits: for example, a smartphone or tablet can contain up to seven reference oscillators. However, the appearance of new technologies such as 5G or autonomous vehicles requires a level of performance that is not attainable by commercial clock technologies. One of the most promising routes to improve performance is the development of clocks based on micro-electromechanical (MEMS) resonators at high frequency (1-5 GHz, tens of GHz in the future). However, building high-performance MEMS resonators in the GHz range is highly challenging, mainly due to the difficulty of detecting their minuscule vibration amplitudes. One promising solution is to use optomechanical detection, using the same principle as gravitational wave detectors but integrated at nanometric scale. This technology, now well mastered at Leti, can be combined with the integration with piezoelectric materials to increase the attainable signal levels. This principle, recently demonstrated by several fundamental research groups, is now mature enough to evolve towards applications, and solves many of the difficulties involved in the implementation of MEMS clocks in the GHz range. The objective of the thesis is to develop a MEMS clock based on this novel optomechanical technology. The thesis will take place in the Microsensors Laboratory of the CEA-Leti, in collaboration with the RF Components Laboratory. The Leti is a pioneer in the implementation of on-chip optomechanical and piezoelectric resonators. The PhD student will work in collaboration with Leti researchers to design the MEMS resonators and their fabrication process, based on an analytical study and finite-element simulations. Then, the student will have the opportunity to contribute to the fabrication of the devices in clean room. Finally, the student will characterize them in the Leti's laboratories, to extract their performance and implement a first demonstrator of optomechanical MEMS clock. The candidate will have a M.Sc. or equivalent degree, with a formation as a generalist engineer or physics, and a specialization on semi-conductor physics, nanotechnology, optics or a closely related field.

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Near-field focusing techniques in inhomogenous media at millimiter wave

Département Systèmes (LETI)

Laboratoire Antennes, Propagation, Couplage Inductif

01-10-2021

SL-DRT-21-0378

antonio.clemente@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

In a huge number of applications such as wireless power transfer (WPT), microwave imaging, industrial control, etc., it is required to collimate, form or focus the electromagnetic radiation in a specific region of the space. Sometimes, this region could be located in the near-field region of the radiating element or surface. In this case, it is referred to as a near-field focused system. With the development of the future ?Beyond 5G? and 6G communication systems, the necessity to focus the radiating beam in the near-field region could be also required in the case of the reconfigurable intelligent surfaces (RIS). These kind of devices, when composed of reconfigurable elements, can be deployed to manipulate the electromagnetic waves and dynamically control and adjust the properties of the propagation channel. Eventually, near-field focusing could be also applied to future medical imaging systems at microwaves. These devices require focusing and collimating the electromagnetic energy in the human body tissues in order to diagnose, monitor and/or treat specific pathologies. In this context, near-field focusing can be used to improve the resolution of the imaging system by optimizing the energy transfer/transmission. The first objective of this thesis is to develop specific numerical tools for the synthesis, design and optimization of near-field focused systems in non-homogeneous media. These techniques will be developed by considering the electromagnetic properties of the media. The synthesis of the aperture field will be done considering modal expansion of the field and the potential vectors theory. After this phase, the synthesis and optimization procedures will be used to design a near-field focused antenna system operating at millimeter and/or sub-THz frequencies (30 - 300 GHz). These antennas will be manufactured and characterized in near-field test ranges. Measurements will validate the developed models for flat radiating apertures in specific scenarios. The possibility to perform measurements in a real applicative context (e.g. cancer detection) will be also considered.

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