no code implementations • 26 Feb 2024 • Yibo Wu, Ulf Gustavsson, Mikko Valkama, Alexandre Graell i Amat, Henk Wymeersch
The use of up to hundreds of antennas in massive multi-user (MU) multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) poses a complexity challenge for digital predistortion (DPD) aiming to linearize the nonlinear power amplifiers (PAs).
no code implementations • 21 May 2023 • Yibo Wu, Luca Sanguinetti, Ulf Gustavsson, Alexandre Graell i Amat, Henk Wymeersch
Cell-Free massive MIMO networks provide huge power gains and resolve inter-cell interference by coherent processing over a massive number of distributed instead of co-located antennas in access points (APs).
no code implementations • 10 May 2022 • Yibo Wu, Ulf Gustavsson, Mikko Valkama, Alexandre Graell i Amat, Henk Wymeersch
In this paper, we propose a convolutional neural network (CNN)-based DPD in the frequency domain, taking place before the precoding, where the dimensionality of the signal space depends on the number of users, instead of the number of BS antennas.
no code implementations • 27 Apr 2022 • Hui Chen, Sina Rezaei Aghdam, Musa Furkan Keskin, Yibo Wu, Simon Lindberg, Andreas Wolfgang, Ulf Gustavsson, Thomas Eriksson, Henk Wymeersch
Location information is expected to be the key to meeting the needs of communication and context-aware services in 6G systems.
no code implementations • 23 Nov 2021 • Yibo Wu, Jinxiang Song, Christian Häger, Ulf Gustavsson, Alexandre Graell i Amat, Henk Wymeersch
We propose an over-the-air digital predistortion optimization algorithm using reinforcement learning.
no code implementations • 6 Apr 2021 • Yibo Wu, Ulf Gustavsson, Alexandre Graell i Amat, Henk Wymeersch
Neural networks (NNs) for multiple hardware impairments mitigation of a realistic direct conversion transmitter are impractical due to high computational complexity.
no code implementations • 24 Dec 2020 • Sina Rezaei Aghdam, Sven Jacobsson, Ulf Gustavsson, Giuseppe Durisi, Christoph Studer, Thomas Eriksson
By studying the spatial characteristics of the distortion, we demonstrate that conventional linear precoding techniques steer nonlinear distortions towards the users.
Information Theory Signal Processing Information Theory
no code implementations • 12 May 2020 • Yibo Wu, Ulf Gustavsson, Alexandre Graell i Amat, Henk Wymeersch
Tracking the nonlinear behavior of an RF power amplifier (PA) is challenging.