67 citations · 334 across the 53 of their papers we have counts for
58 papers
EMF Exposure Mitigation in RIS-Assisted Multi-Beam Communications
Herman L. dos Santos, Cristian J. Vaca-Rubio, Radosław Kotaba +3
This paper proposes a method for reducing {third-party} exposure to electromagnetic fields (EMF) by exploiting the capability of a reconfigurable intelligent surfaces' (RIS) to man…
Uplink Multiplexing of eMBB/URLLC Services Assisted by Reconfigurable Intelligent Surfaces
João Henrique Inacio de Souza, Victor Croisfelt, Radosław Kotaba +2
This letter proposes a scheme assisted by a reconfigurable intelligent surface (RIS) for efficient uplink traffic multiplexing between enhanced mobile broadband (eMBB) and ultra-re…
Raptor-IRSA Grant-free Random Access Protocol for Smart Grids Applications
Angel Esteban Labrador Rivas, Taufik Abrão
This paper deals with the reliability of random access (RA) protocols for massive wireless smart grid communication (m-SGC). We propose and analyze an improved grant-free RA (GF-RA…
Machine Learning-based Methods for Joint {Detection-Channel Estimation} in OFDM Systems
Wilson de Souza Junior, Taufik Abrao
In this work, two machine learning (ML)-based structures for joint detection-channel estimation in OFDM systems are proposed and extensively characterized. Both ML architectures, n…
Improving Spectral Efficiency via Pilot Assignment and Subarray Selection Under Realistic XL-MIMO Channels
Gabriel Avanzi Ubiali, Taufik Abrao, Jose Carlos Marinello
The main requirements for 5G and beyond connectivity include a uniform high quality of service, which can be attained in crowded scenarios by extra-large MIMO (XL-MIMO) systems. An…
NOMA-aided double RIS under Nakagami-m fading: Channel and System Modelling
Wilson de Souza Junior, Taufik Abrao
We investigate the downlink outage performance of double-RIS-aided non-orthogonal multiple access (NOMA), where a near-BS and a near-users RISs setup are deployed. To extend the co…
Improving Random Access with NOMA in mMTC XL-MIMO
Thiago Augusto Bruza Alves, Taufik Abrao
The extra-large multiple-input multiple-output (XL-MIMO) architecture has been recognized as a technology for supporting the massive MTC (mMTC), providing very high-data rates in h…
LSTM-ACB-Based Random Access for Mixed Traffic IoT Networks
Herman L. dos Santos, João H. I. Souza, José Carlos Marinello +1
We propose a novel random access (RA) protocol that accounts for the network traffic in mixed URLLC-mMTC scenarios. By considering an IoT environment under high mMTC traffic demand…
Crowded MTC Random Access in NOMA XL-MIMO
Thiago Augusto Bruza Alves, Taufik Abrão
Massive MIMO is one of the key technologies to support the growth of massive access attempts by devices, such as in massive machine type communication (mMTC). The evolution of ante…
Reconfigurable Intelligent Surfaces to Enable Energy-Efficient IoT Networks
João Henrique Inacio de Souza, José Carlos Marinello Filho, Taufik Abrão +1
In this article, we study the uplink (UL) channel of a cellular network of Internet of Things (IoT) devices assisted by a reconfigurable intelligent surface (RIS) with a limited nu…
Energy Efficiency and Throughput of Random Access Protocols for RIS-Aided IoT Networks
João Henrique Inacio de Souza, José Carlos Marinello Filho, Taufik Abrão +1
Green Internet of Things (IoT) aims to enable a sustainable smart world by making energy efficiency (EE) the main performance indicator for IoT hardware and software. With respect…
OnRMap: An Online Radio Mapping Approach for Large Intelligent Surfaces
Herman L. Santos, Victor Croisfelt, Cristian J. Vaca-Rubio +2
We introduce OnRMap, an online radio mapping (RMap) approach for the sensing and localization of active users (AUs), devices that are transmitting radio signals, and passive elemen…
Randomized Control of Wireless Temporal Coherence via Reconfigurable Intelligent Surface
João Henrique Inacio de Souza, Victor Croisfelt, Fabio Saggese +2
A reconfigurable intelligent surface (RIS) can shape the wireless propagation channel by inducing controlled phase shift variations to the impinging signals. Multiple works have co…
Massive MIMO and NOMA Bits-per-Antenna Efficiency under Power Allocation Policies
Thiago Alves Bruza Alves, Taufik Abrão
A comparative resource allocation analysis in terms of received bits-per-antenna spectral efficiency (SE) and energy efficiency (EE) in downlink (DL) single-cell massive multiple-i…
GA-Aided Directivity in Volumetric and Planar Massive-Antenna Array Design
Bruno Felipe Costa, Taufik Abrão
The problem of directivity enhancement, leading to the increase in the directivity gain over a certain desired angle of arrival/departure (AoA/AoD), is considered in this work. A n…
QoS-Aware User Scheduling in Crowded XL-MIMO Systems Under Non-Stationary Multi-State LoS/NLoS Channels
Joao Henrique Inacio de Souza, Jose Carlos Marinello, Abolfazl Amiri +1
Providing minimum quality-of-service (QoS) in crowded wireless communications systems, with high user density, is challenging due to the network structure with limited transmit pow…
RIS-aided Cooperative FD-SWIPT-NOMA Outage Performance in Nakagami-m Channels
Wilson de Souza Junior, Taufik Abrao
In this work, we investigate reconfigurable intelligent surfaces (RIS)-assisted cooperative non-orthogonal multiple access (C-NOMA) consisting of two paired users, where the phases…
Throughput and Latency in the Distributed Q-Learning Random Access mMTC Networks
Giovanni Maciel Ferreira Silva, Taufik Abrao
In mMTC mode, with thousands of devices trying to access network resources sporadically, the problem of random access (RA) and collisions between devices that select the same resou…
Decentralized Design of Fast Iterative Receivers for Massive and Extreme-Large MIMO Systems
Victor Croisfelt, Taufik Abrão, Abolfazl Amiri +2
Despite the extensive use of a centralized approach to design receivers at the base station for massive multiple-input multiple-output (M-MIMO) systems, their actual implementation…
Exploring the Non-Overlapping Visibility Regions in XL-MIMO Random Access Protocol
José Carlos Marinello Filho, Glauber Brante, Richard Demo Souza +1
The recent extra-large scale massive multiple-input multiple-output (XL-MIMO) systems are seen as a promising technology for providing very high data rates in increased user-densit…
User-Centric Perspective in Random Access Cell-Free Aided by Spatial Separability
Victor Croisfelt, Taufik Abrão, José Carlos Marinello
In a cell-free massive multiple-input multiple-output (CF-mMIMO) network, multiple access points (APs) actively cooperate to serve users' equipment (UEs). We consider how the rando…
Mixed Gibbs Sampling Detector in High-Order Modulation Large-Scale MIMO Systems
Alex Mussi, Taufik Abrão
A neighborhood restricted Mixed Gibbs Sampling (MGS) based approach is proposed for low-complexity high-order modulation large-scale Multiple-Input Multiple-Output (LS-MIMO) detect…
Quasi-Distributed Antenna Selection for Spectral Efficiency Maximization in Subarray Switching XL-MIMO Systems
Joao Henrique Inacio de Souza, Abolfazl Amiri, Taufik Abrao +2
In this paper, we consider the downlink (DL) of a zero-forcing (ZF) precoded extra-large scale massive MIMO (XL-MIMO) system. The base-station (BS) operates with limited number of…
Accelerated Randomized Methods for Receiver Design in Extra-Large Scale MIMO Arrays
Victor Croisfelt Rodrigues, Abolfazl Amiri, Taufik Abrão +2
Massive multiple-input-multiple-output (M-MIMO) features a capability for spatial multiplexing of large number of users. This number becomes even more extreme in extra-large (XL-MI…