75 citations · 167 across the 35 of their papers we have counts for
11 papers · 1 filter
Parametric Channel Estimation for RIS-Assisted Wideband Systems
Alva Kosasih, Ozlem Tugfe Demir, Emil Bjornson
A reconfigurable intelligent surface (RIS) alters the reflection of incoming signals based on the phase-shift configuration assigned to its elements. This feature can be used to im…
Achieving Beamfocusing via Two Separated Uniform Linear Arrays
Alva Kosasih, Özlem Tugfe Demir, Emil Björnson
This paper investigates coordinated beamforming using a modular linear array (MLA), composed of a pair of physically separated uniform linear arrays (ULAs), treated as sub-arrays.…
Graph Neural Network-based End-to-End Learning for Multi-User MIMO Systems
Hao Chang, Hoang Triet Vo, Alva Kosasih +2
End-to-end (E2E) learning has recently been proposed to jointly design the modulator and symbol detector by using deep neural networks (DNNs). However, existing schemes lack suffic…
An Efficient Modified MUSIC Algorithm for RIS-Assisted Near-Field Localization
Parisa Ramezani, Alva Kosasih, Emil Björnson
In this paper, we consider a single-anchor localization system assisted by a reconfigurable intelligent surface (RIS), where the objective is to localize multiple user equipments (…
Symbol-Level Precoding for Near-Field ISAC
Nithin Babu, Alva Kosasih, Christos Masouros +1
The forthcoming 6G and beyond wireless networks are anticipated to introduce new groundbreaking applications, such as Integrated Sensing and Communications (ISAC), potentially leve…
Spatial Frequencies and Degrees of Freedom: Their Roles in Near-Field Communications
Alva Kosasih, Özlem Tuğfe Demir, Nikolaos Kolomvakis +1
As wireless technology begins to utilize physically larger arrays and/or higher frequencies, the transmitter and receiver will reside in each other's radiative near field. This fac…
Enabling 6G Performance in the Upper Mid-Band by Transitioning From Massive to Gigantic MIMO
Emil Björnson, Ferdi Kara, Nikolaos Kolomvakis +3
The initial 6G networks will likely operate in the upper mid-band (7-24 GHz), which has decent propagation conditions but underwhelming new spectrum availability. In this paper, we…
Spatial Correlation Modeling and RS-LS Estimation of Near-Field Channels with Uniform Planar Arrays
Özlem Tuğfe Demir, Alva Kosasih, Emil Björnson
Extremely large aperture arrays (ELAAs) can offer massive spatial multiplexing gains in the radiative near-field region in beyond 5G systems. While near-field channel modeling for…
Accurate Direct Positioning in Distributed MIMO Using Delay-Doppler Channel Measurements
Benjamin J. B. Deutschmann, Christian Nelson, Mikael Henriksson +5
Distributed multiple-input multiple-output (D-MIMO) is a promising technology for simultaneous communication and positioning. However, phase synchronization between multiple access…
Parametric Near-Field Channel Estimation for Extremely Large Aperture Arrays
Alva Kosasih, Özlem Tuğfe Demir, Emil Björnson
Accurate channel estimation is critical to fully exploit the beamforming gains when communicating with extremely large aperture arrays. The propagation distances between the user a…
Nonlinear Distortion Radiated from Large Arrays and Active Reconfigurable Intelligent Surfaces
Nikolaos Kolomvakis, Alva Kosasih, Emil Björnson
Extremely large aperture arrays (ELAAs) and reconfigurable intelligent surfaces (RISs) are candidate enablers to realize connectivity goals for the sixth-generation (6G) wireless n…