Results 91 to 100 of about 105,525 (290)
Dynamic User Grouping-Based NOMA Over Rayleigh Fading Channels
IEEE Access, 2019 With the development of wireless communications and internet of things (IoT), non-orthogonal multiple access (NOMA) has been considered as one of effective schemes to meet the rapidly growing user access requirements.
Yue Yin +4 more
doaj +1 more source
Joint Secure Beamforming for Cognitive Radio Networks with Untrusted Secondary Users
, 2015 In this paper, we consider simultaneous wireless information and power transfer (SWIPT) in orthogonal frequency division multiple access (OFDMA) systems with the coexistence of information receivers (IRs) and energy receivers (ERs).
Liu, Yuan, Zhang, Meng
core +1 more source
Advanced Materials, EarlyView.Electrochemical CO2RR is a key technology for converting CO2 into chemicals, but there remains a gap between “laboratory science” and “engineering practice” in current research. This review establishes a multi‐scale research framework, encompassing atomic‐level characterization, microenvironment regulation, external field‐assisted optimization, and AI ...
Ping Hong +3 more
wiley +1 more source
Time-Frequency Spectrum Sharing Scheme for Next Generation OFDM Systems
EURASIP Journal on Wireless Communications and Networking, 2010 Spectrum sharing and multiple-access techniques are challenging matters for future wireless communication systems. Orthogonal frequency division multiplexing (OFDM) has been considered as the most important physical layer candidate for the next ...
Khalil Ayman +2 more
doaj
A Comparison of CDMA and Frequency Hopping in a Cellular Environment [PDF]
, 1992 This paper compares the performances of direct sequence code division multiple access (CDMA) and frequency hopping (FH) schemes in a cellular multiuser environment.
Mandell, Michael I., McEliece, Robert J.
core +1 more source
Functional Metal Complexes for Solar–Light‐Driven Energy Conversion
Advanced Materials, EarlyView.This review provides an exhaustive summary of the recent advancements of functional metal complexes in solar‐to‐electrical, ‐chemical, and ‐thermal energy conversion, comprising material categories, design strategies, underlying principles of operation, and identified improvement of performances.
Yanyan Qin +3 more
wiley +1 more source
Advanced Materials, EarlyView.Interferometric second‐harmonic generation (SHG) imaging reveals the ubiquitous formation of antiparallel domains in CVD‐grown 2D hexagonal boron nitride. By resolving lattice orientation and SHG phase, hidden domain structures and disorder become visible over large areas. The SHG intensity quantitatively tracks crystalline quality across growth routes,
Yeri Lee +12 more
wiley +1 more source
Applied Sciences, 2019 In this paper, we investigate the energy efficiency (EE) maximization in multi-cell multi-carrier non-orthogonal multiple access (MCMC-NOMA) networks. To achieve this goal, an optimization problem is formulated then the solution is divided into two parts.
Abuzar B. M. Adam +2 more
doaj +1 more source
Dynamic spectrum sharing in orthogonal frequency division multiple access – based cognitive radio
IET Communications, 2010 In this study, a secondary network is underlaid in a conventional downlink orthogonal frequency division multiple access (OFDMA) system to formulate a new implementation of cognitive radio, where spectrum sharing is enabled to improve spectrum utilisation.
Da, B., Ko, C.C.
openaire +1 more source
Deployable 3D‐Printed Vascular Stent with Surface‐Catalysed Endogenous Nitric Oxide Generation
Advanced Materials, EarlyView.A deployable 3D‐printed vascular stent was fabricated with surface‐catalyzed endogenous nitric oxide generation, representing a promising new direction for stent development. The stent can be remotely controlled by magnetic force in its compressed state and fully deployed at the target site using an untethered heat source, potentially eliminating the ...
Kun Zhou +8 more
wiley +1 more source