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Thesis workers - Reduction of Cross-talk Distorsion in 5G

Lund, Sweden
Students and Young Professionals

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Job Description

Date: Oct 31, 2018

Background
Advanced antenna systems (AAS) -also known as massive MIMO- is one of the central enabling radio technologies for 5G cellular systems that significantly boost the provided data rates for data-hungry applications run by densely distributed users. While AAS bring many advantages, they however also bring challenges in contrast to conventional single (or few) antenna radio systems. One of these challenges is the cross talk among different branches in the antenna array caused by antenna mutual coupling. Currently, the signals generated from cross talk and mismatch are prevented by the use of high quality and therefore expensive isolators.

 

Objective
The objective of this thesis is to investigate the feasibility of compensating the RF power amplifiers non-linear distortion and antenna mutual coupling in a sub 6 GHz AAS considering 3GPP requirements on both out-of-band and in-band distortion with relaxed isolation level. These investigations are performed in a Matlab simulation environment.


From our own and other’s previous related studies, it is found possible to compensate for the impairments caused by the RF power amplifiers nonlinear behavior and the antenna mutual coupling by means of digitally pre-distort the AAS input signals. Yet, some level of isolation is still needed to meet the 3GPP sub 6GHz band specifications.

 

Moreover, isolators are essential not only for preventing cross talk between different branches but also for other purposes. Therefore, a step forward is to investigate what level of isolation that is required together with a digital pre-distortion (DPD) that count for mutual coupling and mismatch.

 

Qualifications
We are searching for one or two students with knowledge within, RF technology, microwave engineering and wireless communications.
Further experience with scripting in Matlab is also an important merit.

 

For more information please contact
Mohamed Hamid (supervisor)
Phone: +46 107 139740
E-mail: mohamed.hamid@ericsson.com

 

Martin Isberg (manager)
Phone: +46 107 150970
E-mail: martin.isberg@ericsson.com

 

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Primary country and city: Sweden (SE) || || Lund || Stud&YP

Req ID: 262129