Search Results for author: Ulf Gustavsson

Found 8 papers, 0 papers with code

Time vs. Frequency Domain DPD for Massive MIMO: Methods and Performance Analysis

no code implementations26 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).

Impact of Phase Noise on Uplink Cell-Free Massive MIMO OFDM

no code implementations21 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).

Frequency-domain digital predistortion for Massive MU-MIMO-OFDM Downlink

no code implementations10 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.

MCRB-based Performance Analysis of 6G Localization under Hardware Impairments

no code implementations27 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.

Low Complexity Joint Impairment Mitigation of I/Q Modulator and PA Using Neural Networks

no code implementations6 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.

Distortion-Aware Linear Precoding for Massive MIMO Downlink Systems with Nonlinear Power Amplifiers

no code implementations24 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

Residual Neural Networks for Digital Predistortion

no code implementations12 May 2020 Yibo Wu, Ulf Gustavsson, Alexandre Graell i Amat, Henk Wymeersch

Tracking the nonlinear behavior of an RF power amplifier (PA) is challenging.

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