Proposition de post doctorat M/F : Modeling of power amplifiers for a 5G application, CF-mMIMO

5 Mar 2024
Job Information

Organisation/Company

CNRS

Department

Equipes Traitement de l'Information et Systèmes

Research Field

Engineering
Physics
Technology

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

25 Mar 2024 - 23:59 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

35

Offer Starting Date

1 Jun 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

The mission is to propose a behavioral model of a digital power amplifier which should make it possible to study its impact on the performance of a transmission system for a 5G application using CF-mMIMO technology.

- Develop a behavioral model of a specific power amplifier
- Validate the model by comparison between simulation and measurements
- Manage the implementation in the simulation software of a transmission system for a 5G application using CF-mMIMO technology.

This position is an 18-month post-doctoral contract int the context of PEPR 5G, networks of the future, more particularly in the project named PERSEUS (PC3) which focuses on the technologies, processing, and optimization of “cell-free massive MIMO” networks. (CF-mMIMO) for the frequency band below 7GHz. This post-doctoral is thus part of a larger scientific project including internal and external collaborations from which the candidate will be able to benefit. This work will be carried out in the CELL team of ETIS (UMR8051), under Prof. Myriam Ariaudo's primary supervision and Dr. Cedric Duperrier's co-supervision.
ETIS is a joint lab between CY Cergy Paris Université, ENSEA and CNRS, and a prominent research unit in computer science and information technologies in France.
CELL is an ETIS team, which works in the field of electronics, signal and image processing for the modeling and design of reconfigurable, communicating, reliable and intelligent embedded systems.

Requirements

Research Field

Engineering

Education Level

PhD or equivalent

Research Field

Physics

Education Level

PhD or equivalent

Research Field

Technology

Education Level

PhD or equivalent

Languages

FRENCH

Level

Basic

Research Field

Engineering

Years of Research Experience

None

Research Field

Physics

Years of Research Experience

None

Research Field

Technology

Years of Research Experience

None

Additional Information
Eligibility criteria

Context :
The 5G communication generation, unlike current mobile networks, is not primarily focused on telephony. Indeed, several major applications can use it such as the smart city, the connected home, connected transport, connected health, …

The main specifications set currently are:
- a latency time between 1ms and 5ms
- an increase in data rate (10Gb/s, 10 times higher than 4G)
- an increase in network coverage
- a reduction in consumption (of at least 90%).

Several frequency bands are possible: 24.25-27.25GHz; 31.8-33.4GHz; 37-43.5GHz; 45.5-50.2GHz; 50.4-52.6GHz; 66-76GHz; 81-86GHz. OFDM modulation (Orthogonal Frequency Division Multiplexing), widely adopted for 4G, is favored for the development of 5G even if the latency could impact this choice and push towards alternative solutions.

In current systems, the power amplifier is the component that most impacts consumption and signal integrity (“Dirty RF”). In addition to the usual constraints in terms of consumption and linearity, the new specifications introducing the need for flexibility will impose the power amplifier as the key element in future 5G devices (1)(2)(3).

Objectives :
The objective of this study is to propose a model of power amplifiers allowing subsequently a study of the impact of its characteristics on the performance of a system transmission for a 5G application and CF-mMIMO technology. The architecture of the amplifier chosen is the SCPA (Switch Capacitor Power Amplifier). Techniques to improve the performance of the amplifier will then be studied.

Research program :
The project is part of the PERSEUS program of PEPR 5G.

Digital amplifiers (SCPA) today seem to be an interesting solution compared to traditional amplifiers in terms of efficiency and integration. The structure of these amplifiers based on inverters requires a new evaluation of the faults to be corrected in the transmission chain. For example, what are the memory effects in this type of architecture. In order to properly understand the operation of SCPAs, a simple demonstrator must be produced and measured in order to validate the future model.

The energy efficiency and energy consumption of the proposed solutions will be considered as a guiding design tool of this work.

(1) Jeffrey S. Walling, The Switched-Capacitor Power Amplifier: A Key Enabler for Future Communications Systems, ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference, doi 10.1109/ESSCIRC 2013.8902890

(2) G. Xu, V. Lampu, M. Kosumen, V. Unnikrishnan, J. Ryynänen, M. Valkama and L. Anttila, Digital Polar Transmitters for Massive MIMO : Sum-rate and Power Efficiency Analysis, in IEEE Transactions on Wireless Communications, doi: 10.1109/TWC.2023.3282158

(3) (3) J. Zanen, E. Klumperink and B. Nauta, "A Predistortion-Less Digital MIMO Transmitter With DTC-Based Quadrature Imbalance Compensation," in IEEE Journal of Solid-State Circuits, doi: 10.1109/JSSC.2023.3255741.

Additional comments

Requirements
For this position, you should meet the following requirements:
• Master's degree or equivalent in high frequencies electronics
• Mastery of CAD software :Cadence and ADS Keysight's
• Proficiency in spoken and written English
• Scientific curiosity and desire to work in an interdisciplinary project
• Intellectual rigor and proactive attitude
One or more of the following would be a plus:
• Previous experience in optimization
• Previous international experience

Hiring process
All applications must be submitted via this portal (i.e. Portail emploi CNRS) by [deadline here] and should include:
• CV (1 or 2 pages max)
• Motivation letter including a short description of your background, a statement of your research interests and motivation for this position, and why you think you would be a good fit (1 page)
• Academic transcripts for Undergraduate and Master's degrees
• Two reference letters or contact details of two referees
• One or two samples of scientific writing when available (i.e. publications or project reports; links to publicly available online documents are accepted)
For full consideration, all the items listed above should be included or the absence thereof justified.
Informal inquiries via email prior to full applications are welcome.
Shortlisted candidates will be invited for an interview between January and Febuary 2024.

Website for additional job details

https://emploi.cnrs.fr/Offres/CDD/UMR8051-VIRLAI-003/Default.aspx

Work Location(s)

Number of offers available

1

Company/Institute

Equipes Traitement de l'Information et Systèmes

Country

France

City

CERGY

Geofield

Where to apply

Website

https://emploi.cnrs.fr/Candidat/Offre/UMR8051-VIRLAI-003/Candidater.aspx

Contact

City

CERGY

Website

https://www.etis-lab.fr

STATUS: EXPIRED