963 citations · 4.2k across the 63 of their papers we have counts for
38 papers · 1 filter
Learning to Perform Downlink Channel Estimation in Massive MIMO Systems
Amin Ghazanfari, Trinh Van Chien, Emil Björnson +1
We study downlink (DL) channel estimation in a multi-cell Massive multiple-input multiple-output (MIMO) system operating in a time-division duplex. The users must know their effect…
Autonomous Reconfigurable Intelligent Surfaces Through Wireless Energy Harvesting
Konstantinos Ntontin, Alexandros-Apostolos A. Boulogeorgos, Emil Björnson +7
In this paper, we examine the potential for a reconfigurable intelligent surface (RIS) to be powered by energy harvested from information signals. This feature might be key to reap…
Random Access Protocols for Massive MIMO
Elisabeth de Carvalho, Emil Björnson, Jesper H. Sørensen +2
5G wireless networks are expected to support new services with stringent requirements on data rates, latency and reliability. One novel feature is the ability to serve a dense crow…
Joint Power Allocation and User Association Optimization for Massive MIMO Systems
Trinh Van Chien, Emil Björnson, Erik G. Larsson
This paper investigates the joint power allocation and user association problem in multi-cell Massive MIMO (multiple-input multiple-output) downlink (DL) systems. The target is to…
Random Access Protocol for Massive MIMO: Strongest-User Collision Resolution (SUCR)
Emil Björnson, Elisabeth de Carvalho, Erik G. Larsson +1
Wireless networks with many antennas at the base stations and multiplexing of many users, known as Massive MIMO systems, are key to handle the rapid growth of data traffic. As the…
Three Practical Aspects of Massive MIMO: Intermittent User Activity, Pilot Synchronism, and Asymmetric Deployment
Emil Björnson, Erik G. Larsson
This paper considers three aspects of Massive MIMO (multiple-input multiple-output) communication networks that have received little attention in previous works, but are important…
Random Access for Massive MIMO Systems with Intra-Cell Pilot Contamination
Elisabeth de Carvalho, Emil Bjornson, Erik G. Larsson +1
Massive MIMO systems, where the base stations are equipped with hundreds of antenna elements, are an attractive way to attain unprecedented spectral efficiency in future wireless n…
Adaptive Pilot Clustering in Heterogeneous Massive MIMO Networks
Rami Mochaourab, Emil Björnson, Mats Bengtsson
We consider the uplink of a cellular massive MIMO network. Acquiring channel state information at the base stations (BSs) requires uplink pilot signaling. Since the number of ortho…
Achievable Rate of Rician Large-Scale MIMO Channels with Transceiver Hardware Impairments
Jiayi Zhang, Linglong Dai, Xinling Zhang +2
Transceiver hardware impairments (e.g., phase noise, in-phase/quadrature-phase (I/Q) imbalance, amplifier non-linearities, and quantization errors) have obvious degradation effects…
On the Feasibility of Wireless Energy Transfer Using Massive Antenna Arrays
Salil Kashyap, Emil Björnson, Erik G. Larsson
We illustrate potential benefits of using massive antenna arrays for wireless energy transfer (WET). Specifically, we analyze probability of outage in WET over fading channels when…
Energy Efficiency and Sum Rate when Massive MIMO meets Device-to-Device Communication
Serveh Shalmashi, Emil Björnson, Marios Kountouris +2
This paper considers a scenario of short-range communication, known as device-to-device (D2D) communication, where D2D users reuse the downlink resources of a cellular network to t…
ML Detection in Phase Noise Impaired SIMO Channels with Uplink Training
Antonios Pitarokoilis, Emil Björnson, Erik G. Larsson
The problem of maximum likelihood (ML) detection in training-assisted single-input multiple-output (SIMO) systems with phase noise impairments is studied for two different scenario…
Deploying Dense Networks for Maximal Energy Efficiency: Small Cells Meet Massive MIMO
Emil Björnson, Luca Sanguinetti, Marios Kountouris
How would a cellular network designed for maximal energy efficiency look like? To answer this fundamental question, tools from stochastic geometry are used in this paper to model f…
Optimal Detection in Training Assisted SIMO Systems with Phase Noise Impairments
Antonios Pitarokoilis, Emil Björnson, Erik G. Larsson
In this paper, the problem of optimal maximum likelihood detection in a single user single-input multiple-output (SIMO) channel with phase noise at the receiver is considered. The…
Massive MIMO for Maximal Spectral Efficiency: How Many Users and Pilots Should Be Allocated?
Emil Björnson, Erik G. Larsson, Mérouane Debbah
Massive MIMO is a promising technique to increase the spectral efficiency (SE) of cellular networks, by deploying antenna arrays with hundreds or thousands of active elements at th…
Optimizing Multi-Cell Massive MIMO for Spectral Efficiency: How Many Users Should Be Scheduled?
Emil Björnson, Erik G. Larsson, Mérouane Debbah
Massive MIMO is a promising technique to increase the spectral efficiency of cellular networks, by deploying antenna arrays with hundreds or thousands of active elements at the bas…
Massive MIMO with Non-Ideal Arbitrary Arrays: Hardware Scaling Laws and Circuit-Aware Design
Emil Björnson, Michail Matthaiou, Mérouane Debbah
Massive multiple-input multiple-output (MIMO) systems are cellular networks where the base stations (BSs) are equipped with unconventionally many antennas, deployed on co-located o…
Optimal Linear Precoding in Multi-User MIMO Systems: A Large System Analysis
Luca Sanguinetti, Emil Bjornson, Merouane Debbah +1
We consider the downlink of a single-cell multi-user MIMO system in which the base station makes use of antennas to communicate with single-antenna user equipments (UEs) ra…
Interference-Aware RZF Precoding for Multi Cell Downlink Systems
Axel Müller, Romain Couillet, Emil Björnson +2
Recently, a structure of an optimal linear precoder for multi cell downlink systems has been described in [1, Eq (3.33)]. Other references (e.g., [2,3]) have used simplified versio…
Impact of Residual Transmit RF Impairments on Training-Based MIMO Systems
Xinlin Zhang, Michail Matthaiou, Mikael Coldrey +1
Radio-frequency (RF) impairments, that exist intimately in wireless communications systems, can severely degrade the performance of traditional multiple-input multiple-output (MIMO…
Large System Analysis of the Energy Consumption Distribution in Multi-User MIMO Systems with Mobility
Luca Sanguinetti, Aris L. Moustakas, Emil Bjornson +1
In this work, we consider the downlink of a single-cell multi-user MIMO system in which the base station (BS) makes use of antennas to communicate with single-antenna user…
Asymptotic Analysis of SU-MIMO Channels With Transmitter Noise and Mismatched Joint Decoding
Mikko Vehkaperä, Taneli Riihonen, Maksym A. Girnyk +4
Hardware impairments in radio-frequency components of a wireless system cause unavoidable distortions to transmission that are not captured by the conventional linear channel model…
On the MIMO Capacity with Residual Transceiver Hardware Impairments
Xinlin Zhang, Michail Matthaiou, Emil Björnson +2
Radio-frequency (RF) impairments in the transceiver hardware of communication systems (e.g., phase noise (PN), high power amplifier (HPA) nonlinearities, or in-phase/quadrature-pha…
Optimal Multiuser Transmit Beamforming: A Difficult Problem with a Simple Solution Structure
Emil Björnson, Mats Bengtsson, Björn Ottersten
Transmit beamforming is a versatile technique for signal transmission from an array of antennas to one or multiple users [1]. In wireless communications, the goal is to increas…