Listar GI-GTEC - Artigos por título
Mostrando ítems 138-157 de 193
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On the Feasibility of Time-Modulated Arrays for Digital Linear Modulations: a Theoretical Analysis
(Institute of Electrical and Electronics Engineers, 2014)[Abstract] Wireless communications are widely based on linear digital modulation methods, which introduce the digital baseband information in the amplitude and/or in the phase of a carrier sinusoid. Time-modulated arrays, ... -
On the Multiplicity of Solutions of Taylor Linear Sources Generating Symmetrical Power Patterns with Filled Nulls
(Institute of Electrical and Electronics Engineers, 2004-12)[Abstract] As expressed in earlier works, if filled nulls are required in a power pattern generated by a Taylor line source, their corresponding roots must be complex. This leads to a multiplicity of solutions emerged from ... -
Optimal Synthesis Of Circular Apertures Based On Ludwig Distributions
(Taylor & Francis, 2003-01)[Abstract] Ludwig distributions are a generalization of circular Taylor distributions that generate radiation patterns with wide-angle side lobe levels decaying faster than for Taylor patterns. In this paper we show that ... -
Optimal Synthesis of Line Source Antennas Based On Rhodes Distributions
(Taylor & Francis, 2002)[Abstract] In this paper we show that by means of an appropriate optimization technique the zeros of Rhodes radiation patterns can be perturbed so as to improve or modify pattern and/or the aperture distribution characteristics ... -
Optimizing Uniformly Excited Linear Arrays through Time Modulation
(Institute of Electrical and Electronics Engineers, 2004-12)[Abstract] The letter shows that, by the proper use of time modulation in equispaced linear arrays with uniform excitation distribution, it is possible to maintain the sidelobe zone of the radiated power below a certain - ... -
Performance Analysis of Time-Modulated Arrays for the Angle Diversity Reception of Digital Linear Modulated Signals
(Institute of Electrical and Electronics Engineers, 2017)[Abstract]: Diversity occurs whenever several copies of the same transmitted signal arrive at a receiver. Such a situation allows for improving the performance of a wireless communication system transmitting over a radio ... -
Performance of MIMO systems in measured indoor channels with transmitter noise
(Springer, 2012)This study analyzes the impact of transmitter noise on the performance of multiple-input multiple-output (MIMO) systems with linear and nonlinear receivers and precoders. We show that the performance of MIMO linear and ... -
Perturbation of the Phases of Taylor Field Samples in the Synthesis of Linear and Circular Array Antennas
(Institute of Electrical and Electronics Engineers, 2004-12)[Abstract] Antenna design specifications do not usually restrict the phase of the radiated field. Antenna synthesis techniques generally exploit this freedom only indirectly, but direct phase perturbation can be fruitful. -
Power Efficient Scheduling and Hybrid Precoding for Time Modulated Arrays
(Institute of Electrical and Electronics Engineers, 2020-01-22)[Abstract] We consider power efficient scheduling and precoding solutions for multiantenna hybrid digital-analog transmission systems that use Time-Modulated Arrays (TMAs) in the analog domain. TMAs perform beamforming ... -
Practical latency analysis of a Bluetooth 5 decentralized IoT Opportunistic Edge Computing System for low-cost SBCs
(MDPI, 2022-10)[Abstract]: IoT devices can be deployed almost anywhere, but they usually need to be connected to other IoT devices, either through the Internet or local area networks. For such communications, many IoT devices make use ... -
Propagation modeling for outdoor-to-indoor and indoor-to-indoor wireless links in high-speed train
(Elsevier, 2017)[Abstract]: Nowadays telecommunication companies have shown a great interest in deploying broadband mobile wireless networks in high-speed trains (HSTs) with the aim of supporting both passenger services provisioning as ... -
Proposals and Comparisons from One-Sensor EEG and EOG Human-Machine Interfaces
(MDPI AG, 2021-03-22)[Abstract] Human-Machine Interfaces (HMI) allow users to interact with different devices such as computers or home elements. A key part in HMI is the design of simple non-invasive interfaces to capture the signals associated ... -
QoS constrained power minimization in the MISO broadcast channel with imperfect CSI
(Elsevier, 2017-02)[Abstract]: In this paper we consider the design of linear precoders and receivers in a Multiple-Input Single-Output (MISO) Broadcast Channel (BC). We aim to minimize the transmit power while meeting a set of per-user ... -
QoS constrained power minimization in the multiple stream MIMO broadcast channel
(Elsevier, 2018-02)[Abstract]: This work addresses the design of optimal linear transmit filters for the Multiple Input-Multiple Output (MIMO) Broadcast Channel (BC) when several spatial streams are allocated to each user. We further consider ... -
Rank Constrained Precoding for the Downlink of mmWave Massive MIMO Hybrid Systems
(Institute of Electrical and Electronics Engineers, 2021-02-11)[Abstract] The hybrid design of precoding schemes for millimeter-wave communications allows exploiting the gains by using large antenna array with an affordable hardware cost and power consumption. In this work, we present ... -
Real-time multimedia coding and transmission
(SpringerOpen & European Association for Signal Processing, 2013)[Abstract]: This paper sums up relevant topics covered by the special issue titled ‘Real-Time Multimedia Coding and Transmission’, including efficient content representation, multimedia transmission, hardware and software ... -
Reply to “Comments on ‘Combining Switched TMAs and FDAs to Synthesize Dot-Shaped Beampatterns”’
(Institute of Electrical and Electronics Engineers, 2021)[Abstract]: It is noted that the main innovation contained lies in the consideration of frequency diverse arrays (FDAs) feeding networks made up of time-modulating switches (hence, the term TMA-FDA) instead of phase shifters. ... -
Reverse Engineering and Security Evaluation of Commercial Tags for RFID-Based IoT Applications
(Multidisciplinary Digital Publishing Institute, 2017)[Abstract], The Internet of Things (IoT) is a distributed system of physical objects that requires the seamless integration of hardware (e.g., sensors, actuators, electronics) and network communications in order to collect ... -
Robust Precoding with Bayesian Error Modeling for Limited Feedback MU-MISO Systems
(IEEE, 2010)[Abstract] We consider the robust precoder design for multiuser multiple-input single-output (MU-MISO) systems where the channel state information (CSI) is fed back from the single antenna receivers to the centralized ... -
Robust Precoding with Limited Feedback Design based on Precoding MSE for MU-MISO Systems
(Institute of Electrical and Electronics Engineers, 2012-06)[Abstract] For the separation of the signals in the vector broadcast channel (BC), some information about the channel state is necessary at the transmitter. In many cases, this channel state information (CSI) must be fed ...