no code implementations • 18 Dec 2024 • Alva Kosasih, Ozlem Tugfe Demir, Emil Bjornson
In this paper, we develop a novel parametric ML channel estimator for RIS-assisted wideband systems, which can handle line-of-sight (LOS) paths in the base station (BS)-RIS and RIS-UE links as well as NLOS paths between the UE, BS, and RIS.
no code implementations • 4 Dec 2024 • 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.
no code implementations • 25 Nov 2024 • Hao Chang, Hoang Triet Vo, Alva Kosasih, Branka Vucetic, Wibowo Hardjawana
Multi-user multiple-input multiple-output (MU-MIMO) systems allow multiple users to share the same wireless spectrum.
no code implementations • 21 Sep 2024 • 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 (UEs) placed in the radiative near-field region of the RIS by estimating their azimuth angle-of-arrival (AoA), elevation AoA, and distance to the surface.
no code implementations • 16 Aug 2024 • Nithin Babu, Alva Kosasih, Christos Masouros, Emil Björnson
The forthcoming 6G and beyond wireless networks are anticipated to introduce new groundbreaking applications, such as Integrated Sensing and Communications (ISAC), potentially leveraging much wider bandwidths at higher frequencies and using significantly larger antenna arrays at base stations.
no code implementations • 10 Jul 2024 • Alva Kosasih, Özlem Tuğfe Demir, Nikolaos Kolomvakis, Emil Björnson
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.
no code implementations • 9 Jun 2024 • Özlem Tuğfe Demir, Alva Kosasih, Emil Björnson
It is based on prior knowledge of the three-dimensional coverage region where scattering clusters exists and we derive a tractable one-dimensional integral expression.
no code implementations • 24 Apr 2024 • Benjamin J. B. Deutschmann, Christian Nelson, Mikael Henriksson, Gian Marti, Alva Kosasih, Nuutti Tervo, Erik Leitinger, Fredrik Tufvesson
Distributed multiple-input multiple-output (D-MIMO) is a promising technology for simultaneous communication and positioning.
no code implementations • 31 Jan 2024 • 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.
no code implementations • 23 Jan 2024 • Nikolaos Kolomvakis, Alva Kosasih, Emil Björnson
In this paper, we study the distortion created by nonlinear amplifiers in both ELAAs and active RIS.
no code implementations • 4 Dec 2023 • Amna Irshad, Alva Kosasih, Emil Björnson, Luca Sanguinetti
We optimize the rank and condition number by identifying the optimal antenna spacing in dual-polarized planar antenna arrays with imperfect isolation.
no code implementations • 5 Jul 2023 • Parisa Ramezani, Alva Kosasih, Amna Irshad, Emil Björnson
This article presents the foundational properties of communication in the radiative near-field region and then exemplifies how these properties enable two unprecedented spatial multiplexing schemes: depth-domain multiplexing of multiple users and angular multiplexing of data streams to a single user.
no code implementations • 21 Jun 2023 • Alva Kosasih, Emil Björnson
Furthermore, it is sufficient to characterize the BD for a broadside transmitter, as the beam pattern with a non-broadside transmitter can be approximated by that of a smaller/projected array with a broadside transmitter.
no code implementations • 8 May 2023 • Hao Chang, Alva Kosasih, Wibowo Hardjawana, Xinwei Qu, Branka Vucetic
In this paper, we propose an untrained DNN based on the deep image prior (DIP) and decoder architecture, referred to as D-DIP that replaces the MMSE denoiser in the iterative detector.
no code implementations • 27 Jun 2022 • Alva Kosasih, Xinwei Qu, Wibowo Hardjawana, Chentao Yue, Branka Vucetic
The orthogonal time-frequency space (OTFS) modulation is proposed for beyond 5G wireless systems to deal with high mobility communications.
1 code implementation • 19 Jun 2022 • Alva Kosasih, Vincent Onasis, Vera Miloslavskaya, Wibowo Hardjawana, Victor Andrean, Branka Vucetic
Multi-user multiple-input multiple-output (MU-MIMO) systems can be used to meet high throughput requirements of 5G and beyond networks.
no code implementations • 27 Oct 2021 • Xinwei Qu, Alva Kosasih, Wibowo Hardjawana, Vincent Onasis, Branka Vucetic
Our simulation results show that in contrast to the state-of-the-art OTFS detectors, the proposed detector is able to achieve a BER of less than $10^{-5}$, when SNR is over $14$ dB, under high ICI environments.
no code implementations • 27 Oct 2021 • Alva Kosasih, Vera Miloslavskaya, Wibowo Hardjawana, Victor Andrean, Branka Vucetic
The simulation results show that the proposed detector achieves significant improvements in terms of the bit-error rate and sum spectral efficiency performances as compared to the ones of the state-of-the-art CF detectors.