Search Results for author: Erik G. Larsson

Found 41 papers, 9 papers with code

Reciprocity Calibration of Dual-Antenna Repeaters

no code implementations26 Mar 2024 Erik G. Larsson, Joao Vieira, Pål Frenger

We present a reciprocity calibration method for dual-antenna repeaters in wireless networks.

Faster Convergence with Less Communication: Broadcast-Based Subgraph Sampling for Decentralized Learning over Wireless Networks

no code implementations24 Jan 2024 Daniel Pérez Herrera, Zheng Chen, Erik G. Larsson

Consensus-based decentralized stochastic gradient descent (D-SGD) is a widely adopted algorithm for decentralized training of machine learning models across networked agents.

Scheduling

Over-the-Air Federated Learning with Phase Noise: Analysis and Countermeasures

no code implementations16 Jan 2024 Martin Dahl, Erik G. Larsson

Wirelessly connected devices can collaborately train a machine learning model using federated learning, where the aggregation of model updates occurs using over-the-air computation.

Federated Learning

Decentralized Learning over Wireless Networks with Broadcast-Based Subgraph Sampling

no code implementations24 Oct 2023 Daniel Pérez Herrera, Zheng Chen, Erik G. Larsson

This work centers on the communication aspects of decentralized learning over wireless networks, using consensus-based decentralized stochastic gradient descent (D-SGD).

Scheduling

Dynamic Range Improvement in Bistatic Backscatter Communication Using Distributed MIMO

no code implementations30 Jun 2023 Ahmet Kaplan, Joao Vieira, Erik G. Larsson

Backscatter communication (BSC) is a promising solution for Internet-of-Things (IoT) connections due to its low-complexity, low-cost, and energy-efficient solution for sensors.

Direct Link Interference Suppression for Bistatic Backscatter Communication in Distributed MIMO

no code implementations11 Jun 2023 Ahmet Kaplan, Joao Vieira, Erik G. Larsson

Finally, simulation results show that the required dynamic range of the system is significantly decreased, and the detection performance of the BD symbol is increased, by the proposed algorithm compared to a system not using beamforming at the CE.

Decentralized Learning over Wireless Networks: The Effect of Broadcast with Random Access

no code implementations12 May 2023 Zheng Chen, Martin Dahl, Erik G. Larsson

In particular, we investigate the impact of broadcast transmission and probabilistic random access policy on the convergence performance of D-SGD, considering the broadcast nature of wireless channels and the link dynamics in the communication topology.

Using Mobile Phones for Participatory Detection and Localization of a GNSS Jammer

no code implementations3 May 2023 Glädje Karl Olsson, Sara Nilsson, Erik Axell, Erik G. Larsson, Panos Papadimitratos

Evaluations are performed using a Samsung S20+ mobile phone as participatory sensor and a Spirent GSS9000 GNSS simulator to generate GNSS and jamming signals.

Position

Dynamic Scheduling for Federated Edge Learning with Streaming Data

no code implementations2 May 2023 Chung-Hsuan Hu, Zheng Chen, Erik G. Larsson

In this work, we consider a Federated Edge Learning (FEEL) system where training data are randomly generated over time at a set of distributed edge devices with long-term energy constraints.

Scheduling

Phase Calibration of Distributed Antenna Arrays

no code implementations11 Apr 2023 Erik G. Larsson, Joao Vieira

Antenna arrays can be either reciprocity calibrated (R-calibrated), which facilitates reciprocity-based beamforming, or fully calibrated (F-calibrated), which additionally facilitates transmission and reception in specific physical directions.

25 Years of Signal Processing Advances for Multiantenna Communications

no code implementations5 Apr 2023 Emil Björnson, Yonina C. Eldar, Erik G. Larsson, Angel Lozano, H. Vincent Poor

In 1998, mobile phones were still in the process of becoming compact and affordable devices that could be widely utilized in both developed and developing countries.

On the Road to 6G: Visions, Requirements, Key Technologies and Testbeds

no code implementations28 Feb 2023 Cheng-Xiang Wang, Xiaohu You, Xiqi Gao, Xiuming Zhu, Zixin Li, Chuan Zhang, Haiming Wang, Yongming Huang, Yunfei Chen, Harald Haas, John S. Thompson, Erik G. Larsson, Marco Di Renzo, Wen Tong, Peiying Zhu, Xuemin, Shen, H. Vincent Poor, Lajos Hanzo

A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc.

Scheduling and Aggregation Design for Asynchronous Federated Learning over Wireless Networks

no code implementations14 Dec 2022 Chung-Hsuan Hu, Zheng Chen, Erik G. Larsson

Federated Learning (FL) is a collaborative machine learning (ML) framework that combines on-device training and server-based aggregation to train a common ML model among distributed agents.

Federated Learning Scheduling

Over-the-Air Federated Learning with Privacy Protection via Correlated Additive Perturbations

no code implementations5 Oct 2022 Jialing Liao, Zheng Chen, Erik G. Larsson

In this work, we aim at minimizing privacy leakage to the adversary and the degradation of model accuracy at the edge server at the same time.

Federated Learning

Detecting Abrupt Changes in Channel Covariance Matrix for MIMO Communication

no code implementations5 Jul 2022 Runnan Liu, Liang Liu, Dazhi He, Wenjun Zhang, Erik G. Larsson

Our paper aims to adopt the classic change detection theory to detect the change in the channel covariance matrix as accurately and quickly as possible such that the new covariance matrix can be re-estimated in time.

Change Detection

Downlink Power Allocation in Massive MIMO via Deep Learning: Adversarial Attacks and Training

no code implementations14 Jun 2022 B. R. Manoj, Meysam Sadeghi, Erik G. Larsson

The successful emergence of deep learning (DL) in wireless system applications has raised concerns about new security-related challenges.

regression

Participatory Sensing for Localization of a GNSS Jammer

no code implementations29 Apr 2022 Glädje Karl Olsson, Erik Axell, Erik G. Larsson, Panos Papadimitratos

The notion of participatory sensing, or crowdsensing, is that a large ensemble of voluntary contributors provides the measurements, rather than relying on dedicated sensing infrastructure.

Universal Adversarial Attacks on Neural Networks for Power Allocation in a Massive MIMO System

no code implementations10 Oct 2021 Pablo Millán Santos, B. R. Manoj, Meysam Sadeghi, Erik G. Larsson

Deep learning (DL) architectures have been successfully used in many applications including wireless systems.

regression

Detection of Abrupt Change in Channel Covariance Matrix for Multi-Antenna Communication

1 code implementation9 Sep 2021 Runnan Liu, Liang Liu, Dazhi He, Wenjun Zhang, Erik G. Larsson

This result verifies the possibility to detect the channel covariance change both accurately and quickly in practice.

Change Detection

Learning to Perform Downlink Channel Estimation in Massive MIMO Systems

no code implementations6 Sep 2021 Amin Ghazanfari, Trinh Van Chien, Emil Björnson, Erik G. Larsson

The second one is a deep-learning-based approach that uses a neural network to identify a mapping between the available information and the effective channel gain.

Device Scheduling and Update Aggregation Policies for Asynchronous Federated Learning

no code implementations23 Jul 2021 Chung-Hsuan Hu, Zheng Chen, Erik G. Larsson

Federated Learning (FL) is a newly emerged decentralized machine learning (ML) framework that combines on-device local training with server-based model synchronization to train a centralized ML model over distributed nodes.

Federated Learning Scheduling

Moving Object Classification with a Sub-6 GHz Massive MIMO Array using Real Data

no code implementations9 Feb 2021 B. R. Manoj, Guoda Tian, Sara Gunnarsson, Fredrik Tufvesson, Erik G. Larsson

Classification between different activities in an indoor environment using wireless signals is an emerging technology for various applications, including intrusion detection, patient care, and smart home.

Classification General Classification +1

Adversarial Attacks on Deep Learning Based Power Allocation in a Massive MIMO Network

no code implementations28 Jan 2021 B. R. Manoj, Meysam Sadeghi, Erik G. Larsson

In this paper, we extend this to regression problems and show that adversarial attacks can break DL-based power allocation in the downlink of a massive multiple-input-multiple-output (maMIMO) network.

Consensus-Based Distributed Computation of Link-Based Network Metrics

no code implementations29 Dec 2020 Zheng Chen, Erik G. Larsson

Average consensus algorithms have wide applications in distributed computing systems where all the nodes agree on the average value of their initial states by only exchanging information with their local neighbors.

Distributed Computing Distributed, Parallel, and Cluster Computing Social and Information Networks Signal Processing

Massively Distributed Antenna Systems with Non-Ideal Optical Fiber Front-hauls: A Promising Technology for 6G Wireless Communication Systems

no code implementations18 Aug 2020 Lisu Yu, Jingxian Wu, Andong Zhou, Erik G. Larsson, Pingzhi Fan

Employing massively distributed antennas brings radio access points (RAPs) closer to users, thus enables aggressive spectrum reuse that can bridge gaps between the scarce spectrum resource and extremely high connection densities in future wireless systems.

Symbiotic Radio: Cognitive Backscattering Communications for Future Wireless Networks

no code implementations3 Jul 2020 Ying-Chang Liang, Qianqian Zhang, Erik G. Larsson, Geoffrey Ye Li

To exploit the full potential of SR, in this paper, we address three fundamental tasks in SR: (1) enhancing the backscattering link via active load; (2) achieving highly reliable communications through joint decoding; and (3) capturing PTx's RF signals using reconfigurable intelligent surfaces.

Max-Min Optimal Beamforming for Cell-Free Massive MIMO

no code implementations10 Jun 2020 Andong Zhou, Jingxian Wu, Erik G. Larsson, Pingzhi Fan

This letter develops an optimum beamforming method for downlink transmissions in cell-free massive multiple-input multiple-output (MIMO) systems, which employ a massive number of distributed access points to provide concurrent services to multiple users.

Weighted Sum-Rate Maximization for Reconfigurable Intelligent Surface Aided Wireless Networks

2 code implementations27 Dec 2019 Huayan Guo, Ying-Chang Liang, Jie Chen, Erik G. Larsson

Our objective is to maximize the weighted sum-rate (WSR) of all users by joint designing the beamforming at the access point (AP) and the phase vector of the RIS elements, while both the perfect channel state information (CSI) setup and the imperfect CSI setup are investigated.

Signal Processing

Optimizing Information Freshness in a Multiple Access Channel with Heterogeneous Devices

no code implementations10 Oct 2019 Zheng Chen, Nikolaos Pappas, Emil Björnson, Erik G. Larsson

We formulate an optimization problem that aims at minimizing the average age of information (AoI) of the EH node subject to the queue stability condition of the grid-connected node.

Information Theory Networking and Internet Architecture Information Theory

Intelligent Reflecting Surface vs. Decode-and-Forward: How Large Surfaces Are Needed to Beat Relaying?

1 code implementation10 Jun 2019 Emil Björnson, Özgecan Özdogan, Erik G. Larsson

The rate and energy efficiency of wireless channels can be improved by deploying software-controlled metasurfaces to reflect signals from the source to the destination, especially when the direct path is weak.

Information Theory Information Theory

Weighted Sum-Rate Optimization for Intelligent Reflecting Surface Enhanced Wireless Networks

2 code implementations20 May 2019 Huayan Guo, Ying-Chang Liang, Jie Chen, Erik G. Larsson

In addition, we consider a practical IRS assumption, in which the passive elements can only shift the incident signal to discrete phase levels.

Physical Adversarial Attacks Against End-to-End Autoencoder Communication Systems

1 code implementation22 Feb 2019 Meysam Sadeghi, Erik G. Larsson

We show that end-to-end learning of communication systems through deep neural network (DNN) autoencoders can be extremely vulnerable to physical adversarial attacks.

Power Control in Cellular Massive MIMO with Varying User Activity: A Deep Learning Solution

1 code implementation11 Jan 2019 Trinh Van Chien, Thuong Nguyen Canh, Emil Björnson, Erik G. Larsson

We first consider the sum spectral efficiency (SE) optimization problem for systems with a dynamically varying number of active users.

Information Theory Information Theory

How Energy-Efficient Can a Wireless Communication System Become?

1 code implementation4 Dec 2018 Emil Björnson, Erik G. Larsson

Is this roughly as energy-efficient future systems (5G and beyond) can become, or are we still far from the physical limits?

Information Theory Information Theory

Adversarial Attacks on Deep-Learning Based Radio Signal Classification

no code implementations23 Aug 2018 Meysam Sadeghi, Erik G. Larsson

Deep learning (DL), despite its enormous success in many computer vision and language processing applications, is exceedingly vulnerable to adversarial attacks.

Classification General Classification

Massive MIMO in Sub-6 GHz and mmWave: Physical, Practical, and Use-Case Differences

1 code implementation29 Mar 2018 Emil Björnson, Liesbet Van der Perre, Stefano Buzzi, Erik G. Larsson

The use of base stations (BSs) and access points (APs) with a large number of antennas, called Massive MIMO (multiple-input multiple-output), is a key technology for increasing the capacity of 5G networks and beyond.

Information Theory Information Theory

A Random Access Protocol for Pilot Allocation in Crowded Massive MIMO Systems

1 code implementation14 Apr 2016 Emil Björnson, Elisabeth de Carvalho, Jesper H. Sørensen, Erik G. Larsson, Petar Popovski

The Massive MIMO (multiple-input multiple-output) technology has great potential to manage the rapid growth of wireless data traffic.

Information Theory Networking and Internet Architecture Information Theory

Kernel Methods for Accurate UWB-Based Ranging with Reduced Complexity

no code implementations10 Nov 2015 Vladimir Savic, Erik G. Larsson, Javier Ferrer-Coll, Peter Stenumgaard

For this problem, ultra-wideband (UWB) technology can provide the most accurate range estimates, which are required for range-based positioning.

GPR

Fingerprinting-Based Positioning in Distributed Massive MIMO Systems

no code implementations1 Sep 2015 Vladimir Savic, Erik G. Larsson

Location awareness in wireless networks may enable many applications such as emergency services, autonomous driving and geographic routing.

Autonomous Driving

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