Description
Date depot: 21 mars 2018
Titre: Techniques de correction des imperfections de la chaîne RF pour les formes d'ondes multiporteuses post 5G
Directeur de thèse:
Daniel ROVIRAS (CEDRIC)
Domaine scientifique: Sciences et technologies de l'information et de la communication
Thématique CNRS : Non defini
Resumé:
The main objectives of this thesis are the following: 1.Identify the
major RF impairments that can occur in broadband multicarrier waveforms that
would potentially be adopted for beyond 5G systems. 2.Study the effect of these RF
impairments on the performance of the wireless systems in terms of in-band and
out-off-band distortions. In this part, a special care will be given to
characterize the nonlinear distortion induced by some realistic PA models. The
in-band and out-off-band PA effects will be studied on the most pertinent
waveforms contenders for 5G. A concern will be given to theoretical studies,
aiming to characterize, in closed-form, the resulting signal distortion levels
and system level impairment impact due to the different imperfections, in terms
of bit-error-rate (BER), power spectral density (PSD) re-growth,
adjacent channel leakage ratio (ACLR) and other related performance indicators. 3.Design dedicated signal processing based algorithms to mitigate Dirty-RF
impairments on both the transmitter and the receiver sides of a 5G
communication system. In this part of the work, more emphasis will be given to
improve the performance of the selected multicarrier waveforms in presence of
nonlinear HPA. This objective can be reached by adopting one of the following
approaches: * Apply a peak to average power ratio (PAPR) reduction technique
followed by a predistortion one to improve the trade-off between linearity and
efficiency in RF power amplifier, * Combine the PAPR reduction and the
predistortion techniques and propose a joint optimized algorithm increasing the
HPA performances.
Doctorant.e: Cheng Xinying