no code implementations • 13 Mar 2024 • Vu Nguyen Ha, Duy H. N. Nguyen, Juan C. -M. Duncan, Jorge L. Gonzalez-Rios, Juan A. Vasquez, Geoffrey Eappen, Luis M. Garces-Socarras, Rakesh Palisetty, Symeon Chatzinotas, Bjorn Ottersten
This paper introduces a joint optimization framework for user-centric beam selection and linear precoding (LP) design in a coordinated multiple-satellite (CoMSat) system, employing a Digital-Fourier-Transform-based (DFT) beamforming (BF) technique.
no code implementations • 20 Feb 2024 • Chunmei Xu, Shengheng Liu, Yongming Huang, Bjorn Ottersten, Dusit Niyato
Extensive simulation results are presented to demonstrate the effectiveness of the proposed random aggregate beamforming-based scheme as well as the refined method.
no code implementations • 18 Oct 2023 • Marcele O. K. Mendonca, Flor G. Ortiz-Gomez, Jorge Querol, Eva Lagunas, Juan A. Vásquez Peralvo, Victor Monzon Baeza, Symeon Chatzinotas, Bjorn Ottersten
Satellite communications, essential for modern connectivity, extend access to maritime, aeronautical, and remote areas where terrestrial networks are unfeasible.
no code implementations • 15 May 2023 • Arsham Mostaani, Thang X. Vu, Hamed Habibi, Symeon Chatzinotas, Bjorn Ottersten
Numerical results show striking improvements in reducing the computational complexity of obtaining VoI needed for the TOCD in a MAS problem without compromising the average return performance of the MAS.
no code implementations • 25 Sep 2022 • Zhen Gao, Xingyu Zhou, Jingjing Zhao, Juan Li, Chunli Zhu, Chun Hu, Pei Xiao, Symeon Chatzinotas, Derrick Wing Kwan Ng, Bjorn Ottersten
With the blooming of Internet-of-Things (IoT), we are witnessing an explosion in the number of IoT terminals, triggering an unprecedented demand for ubiquitous wireless access globally.
no code implementations • 3 Feb 2022 • Wali Ullah Khan, Muhammad Ali Jamshed, Asad Mahmood, Eva Lagunas, Symeon Chatzinotas, Bjorn Ottersten
Then the RSUs transmit the superimposed signal to their serving vehicles in the second time slot exploiting decode and forward protocol.
no code implementations • 3 Feb 2022 • Wali Ullah Khan, Muhammad Ali Jamshed, Eva Lagunas, Symeon Chatzinotas, Xingwang Li, Bjorn Ottersten
Automotive-Industry 5. 0 will use beyond fifth-generation (B5G) technologies to provide robust, computationally intelligent, and energy-efficient data sharing among various onboard sensors, vehicles, and other devices.
no code implementations • 1 Feb 2022 • Wali Ullah Khan, Eva Lagunas, Asad Mahmood, Symeon Chatzinotas, Bjorn Ottersten
To enhance the effective gain, the signal delivery from satellite to the ground mobile terminal is also assisted by RIS which smartly shift the phase of the signal towards ground terminal.
no code implementations • 4 Jul 2021 • Van-Dinh Nguyen, Symeon Chatzinotas, Bjorn Ottersten, Trung Q. Duong
data, users' heterogeneity), we first propose an efficient FL algorithm based on Federated Averaging (called FedFog) to perform the local aggregation of gradient parameters at fog servers and global training update at the cloud.
no code implementations • 18 Jun 2021 • Shicong Liu, Zhen Gao, Yongpeng Wu, Derrick Wing Kwan Ng, Xiqi Gao, Kai-Kit Wong, Symeon Chatzinotas, Bjorn Ottersten
The rapid development of communication technologies in the past decades has provided immense vertical opportunities for individuals and enterprises.
no code implementations • 18 Jan 2021 • Thang X. Vu, Symeon Chatzinotas, Van-Dinh Nguyen, Dinh Thai Hoang, Diep N. Nguyen, Marco Di Renzo, Bjorn Ottersten
We investigate the performance of multi-user multiple-antenna downlink systems in which a BS serves multiple users via a shared wireless medium.
Information Theory Information Theory
no code implementations • 20 Nov 2020 • Juan Merlano Duncan, Liz Martinez-Marrero, Jorge Querol, Sumit Kumar, Adriano Camps, Symeon Chatzinotas, Bjorn Ottersten
Phase, frequency, and time synchronization are crucial requirements for many applications, such as multi-static remote sensing and communication systems.
no code implementations • 2 Nov 2020 • Bhavani Shankar Mysore, Eva Lagunas, Symeon Chatzinotas, Bjorn Ottersten
Precoding has stood out as a promising multi-user transmission technique to meet the emerging throughput demand of satellite communication systems while awaiting the technological maturity for exploiting higher bands.
no code implementations • 26 Oct 2020 • Alexandre Saint, Anis Kacem, Kseniya Cherenkova, Konstantinos Papadopoulos, Julian Chibane, Gerard Pons-Moll, Gleb Gusev, David Fofi, Djamila Aouada, Bjorn Ottersten
Additionally, two unique datasets of 3D scans are proposed, to provide raw ground-truth data for the benchmarks.
no code implementations • 6 Sep 2020 • Shree Krishna Sharma, Jorge Querol, Nicola Maturo, Symeon Chatzinotas, Bjorn Ottersten
Future generation wireless networks are targeting the convergence of fixed, mobile and broadcasting systems with the integration of satellite and terrestrial systems towards utilizing their mutual benefits.
no code implementations • 1 Aug 2020 • Dinh-Hieu Tran, Van-Dinh Nguyen, Sumit Gautam, Symeon Chatzinotas, Thang X. Vu, Bjorn Ottersten
In this context, we aim to maximize the number of served IoT devices by jointly optimizing bandwidth, power allocation, and the UAV trajectory while satisfying each device's requirement and the UAV's limited storage capacity.
no code implementations • 24 Jun 2020 • Yaxiong Yuan, Lei Lei, Thang Xuan Vu, Symeon Chatzinotas, Sumei Sun, Bjorn Ottersten
The conventional RL/DRL, e. g., deep Q-learning, however, is limited in dealing with two main issues in constrained combinatorial optimization, i. e., exponentially increasing action space and infeasible actions.
no code implementations • 2 Oct 2018 • Arsham Mostaani, Osvaldo Simeone, Symeon Chatzinotas, Bjorn Ottersten
In this work, it is demonstrated that the performance of the collaborative task can be improved if the agents learn jointly how to communicate and to act, even in the presence of a delay in the communication channel.
Information Theory Multiagent Systems Information Theory
no code implementations • 4 Aug 2018 • Eman Ahmed, Alexandre Saint, Abd El Rahman Shabayek, Kseniya Cherenkova, Rig Das, Gleb Gusev, Djamila Aouada, Bjorn Ottersten
3D data is a valuable asset the computer vision filed as it provides rich information about the full geometry of sensed objects and scenes.
no code implementations • CVPR 2017 • Michel Antunes, Joao P. Barreto, Djamila Aouada, Bjorn Ottersten
The article concerns the automatic calibration of a camera with radial distortion from a single image.
no code implementations • CVPR 2016 • Girum G. Demisse, Djamila Aouada, Bjorn Ottersten
The use of direct product Lie groups to represent curved shapes led to an explicit formula for geodesic curves and the formulation of a similarity metric between shapes by the L2-norm on the Lie algebra.
no code implementations • 18 May 2015 • Alejandro Correa Bahnsen, Djamila Aouada, Bjorn Ottersten
Moreover, we propose two new cost-sensitive combination approaches; cost-sensitive weighted voting and cost-sensitive stacking, the latter being based on the cost-sensitive logistic regression method.