Results 61 to 70 of about 5,536 (185)
Short-range ultrasonic communications in air using quadrature modulation [PDF]
, 2009 A study has been undertaken of ultrasonic communications methods in air, using a quadrature modulation method. Simulations were first performed to establish the likely performance of quadrature phase shift keying over the limited bandwidth available in ...
Green, Roger, Hutchins, David A., Li, C.
core +1 more source
Brain Pathology, Volume 35, Issue 2, March 2025.Brain pericyte subsets play distinct roles in regulating the blood–brain barrier and Alzheimer's disease. Abstract Although the concept that the blood–brain barrier (BBB) plays an important role in the etiology and pathogenesis of Alzheimer's disease (AD) has become increasingly accepted, little is known yet about how it actually contributes.
Diana G. Bohannon +8 more
wiley +1 more source
On the EVM computation of arbitrary clipped multi-carrier signals
EURASIP Journal on Advances in Signal Processing, 2011 A common figure of merit in multi-carrier systems is the error vector magnitude (EVM). A method for EVM computation of a multi-carrier signal without any underlying model (e.g., the Gaussianity assumption) was proposed in a previous work of the authors ...
Kotzer Igal, Litsyn Simon
doaj
Optimal Large-MIMO Data Detection with Transmit Impairments
, 2015 Real-world transceiver designs for multiple-input multiple-output (MIMO) wireless communication systems are affected by a number of hardware impairments that already appear at the transmit side, such as amplifier non-linearities, quantization artifacts ...
Ghods, Ramina +3 more
core +1 more source
UMTS radio-over-fiber pico-cell interconnection employing uncooled DFB lasers for multi-mode fibre modulation bandwidth enhancement [PDF]
, 2009 This paper analyzes experimentally the use of distributed feedback lasers (DFB) in order to increase modulation bandwidth in multimode fibres, enabling 3 km bidirectional radio-over-multimode fibre UMTS transmission in a frequency-division duplexing (FDD)
Alemany, Ruben +2 more
core +1 more source
Distributed remote antenna unit with selection‐based of (RoF‐IoT) paradigm: Performance improvement
IET Communications, Volume 19, Issue 1, January/December 2025.Abstract Mixing the wireless medium with fiber optics can form a new communication system called a radio‐over‐fiber (RoF) network; it is a promising solution that can provide high bandwidth and a reliable connection between numerous sensors in wireless sensor networks (WSN) and the central office (base station) within a particular area.
Shakir Salman Ahmad +2 more
wiley +1 more source
Aerogel Antennas Communications Study Using Error Vector Magnitude Measurements [PDF]
This paper discusses an aerogel antennas communication study using error vector magnitude (EVM) measurements. The study was performed using 4x2 element polyimide (PI) aerogel-based phased arrays designed for operation at 5 GHz as transmit (Tx) and ...
Meador, Mary Ann B. +2 more
core +3 more sources
Theoretical and experimental design of an alternative system to 2 x 2 MIMO for LTE over 60 km directly modulated RoF link [PDF]
, 2012 Relay nodes (RN) are used as an important structure to extend the coverage of the Third Generation Partnership Program’s Long Term Evolution (3GPP-LTE). The promising technology as the interface between eNodeB (eNB) and RN is radio-over-fibre (RoF), due ...
Ghassemlooy, Zabih +3 more
core +1 more source
IET Communications, Volume 19, Issue 1, January/December 2025.This study proposes a 3D stochastic geometry model for intelligent reflecting surface (IRS)‐assisted communication systems utilizing large antenna transmitters with cylindrical array configurations. The model incorporates hardware impairments and evaluates spectral efficiency under both ideal and non‐ideal conditions.
Antwi Owusu Agyeman +5 more
wiley +1 more source
Linearity of millimetre‐wave graded‐channel GaN HEMTs under quadrature amplitude modulation
Electronics Letters, Volume 61, Issue 1, January/December 2025.We report large‐signal linearity and power‐added‐efficiency of high‐speed graded‐channel GaN‐based high‐electron‐mobility transistors at 30 GHz under 64‐QAM and 256‐QAM. These graded‐channel GaN high‐electron‐mobility transistors show an fT of 160 GHz and peak power‐added efficiency of 6% at 30 GHz.
Jeong‐sun Moon +5 more
wiley +1 more source