Προκήρυξη:

Title:

Signal processing aspects of joint energy and spectrum collaboration for future wireless communications networks

Laboratory:

IETR – Institute of Electronics and Telecommunications of Rennes.

The PhD Student will be located in CentraleSupélec premises in Rennes.

Abstract:

With wireless and mobile communications applications playing a crucial role in everyday life, meeting the connectivity and throughput demands that is for foreseen for 5G and beyond 5G networks requires efficient spectrum sharing techniques. As a result, aggressive frequency reuse and new Non-Orthogonal Multiple Access (NOMA) schemes [1] are expected to be in the spotlight of the wireless communications research community.

At the same time, the pressing need for reducing carbon emissions, calls for new energy efficient/energy aware communications techniques. To meet this need, currently several solutions are investigated exploiting renewable energy resources and renewable energy sharing [2], RF-signal energy harvesting/recycling, and advanced Base Station on-off switching techniques as means towards achieving energy efficiency.

While both the above research areas are being currently investigated, the potential coming from the fullyjoint investigation of spectrum and energy resources still remains unexploited. The focus of this PhD will be on the intersection of these two research areas with particular focus on the following research direction:

Design of collaborative/multipurpose signal processing/physical layer techniques

The use of non-orthogonal spectrum sharing techniques along with the expectation for massive connectivity demand, not only allows for the efficient exploitation of bandwidth resources by multiple users, but also contributes towards creating an interference-rich environment that can be used by power-limited users for energy harvesting purposes. With this in mind, this PhD thesis will investigate the design of physical layer (e.g. beamforming) techniques aiming at tackling the multifaceted problem of minimizing power consumption while satisfying 1) throughput constraints as set by active (content requesting) users, as well as 2) received/harvested energy constraints as set by power-limited RF-energy harvesting users. Scenarios accounting for limited Channel State Information (CSI) availability will be considered, as well as scenarios accounting for different levels of CSI availability. Initially, the focus will be on the design of techniques not presuming Base Station collaboration. Extending this initial approach, the aim will shift towards investigating the benefits of Base Station collaboration. Different collaboration policies will be considered exploiting: 1) Energy based collaboration exploiting architectures for jointly handling/trading renewable energy resources commonly accessible to the network base stations (e.g. the energy aggregator based architecture introduced in [2]), 2) Spectrum based collaboration based on the use of Multicell designs exploiting Multicell-MIMO techniques. The benefits and limitations of system designs based on these two policies will be investigated, and best practices accounting for CSI exchange and computational complexity limitations will be recognized.

[1] . Ding et al., "Application of Non-Orthogonal Multiple Access in LTE and 5G Networks," in IEEE Communications Magazine, vol. 55, no. 2, pp. 185-191, February 2017.

[2] J. Xu, L. Duan and R. Zhang, "Cost-aware green cellular networks with energy and communication cooperation," in IEEE Communications Magazine, vol. 53, no. 5, pp. 257-263, May 2015.

Keywords:

Wireless Communications, Energy aware communications, Spectrum and Energy Sharing, Multiple Access Schemes, Interference mitigation/coordination techniques, Signal Processing, Energy Harvesting, Energy recycling.

Contacts and advisors:

Georgios ROPOKIS

Assistant Professor – CentraleSupélec

Campus of Rennes IETR Laboratory

e-mail: ropokisg@tcd.ie or gropokis@gmail.com

Phone: +353 874556707

Christophe MOY

Professor – University of Rennes 1

IETR Laboratory

e-mail: christophe.moy@univ-rennes1.fr

Phone: +33 (0)2 23 23 54 37

https://moychris.wordpress.com/

Expected Qualifications for candidates:

Applicants for the PhD position (3 years) must have undergraduate and/or postgraduate studies on a topic related to wireless communications (e.g. Electrical and/or Electronic Engineering), good background on digital/wireless communications and signal processing for wireless communications as well as strong mathematical skills. French speaking and/or writing is not required but may be a plus.

Location:

The thesis will be carried out at Signals, Communications & Embedded Electronics (SCEE) research group (http://www.rennes.supelec.fr/ren/rd/scee/ in CentraleSupelec premises (Campus of Rennes), in France, colocated on the same campus with University of Rennes 1.

Grant:

The grant is a “contrat doctoral” from French Ministry of Research, which is set to 1400 € net/month.

Application:

To apply send your CV (including contact details, and references letters), copies of degree certificates, academic transcripts, and English language test certificates (if applicable) along with a motivation letter to: Georgios ROPOKIS (ropokisg@tcd.ie and gropokis@gmail.com) and Christophe MOY (christophe.moy@univ-rennes1.f) as soon as possible, in order to start interviews, but anyway before the 20 of May 2018. An interview (Skype or visit) will have to be done with both advisors before the 1st of June. Please indicate if you can come or should do this interview remotely (by Skype or other). Ecole Doctorale MathSTIC will inform candidates on the final decision to give the grant no later than the 22th of June.

Application deadline: 20 May 2018

Feedback on final decision: 22 June 2018 (the latest)