Results 21 to 30 of about 305,430 (305)

Spectral Efficiency Maximization for Deliberate Clipping-Based Multicarrier Faster-Than-Nyquist Signaling

open access: yesIEEE Access, 2018
High peak-to-average power ratio (PAPR) is one of the common drawbacks of multicarrier signals at the transmitter. In this paper, we investigate the PAPR reduction of spectral efficient multicarrier faster-than-Nyquist (MFTN) signals, where the PAPR ...
Siming Peng   +4 more
doaj   +1 more source

A Parallel Decoding Algorithm for Short Polar Codes Based on Error Checking and Correcting

open access: yesThe Scientific World Journal, 2014
We propose a parallel decoding algorithm based on error checking and correcting to improve the performance of the short polar codes. In order to enhance the error-correcting capacity of the decoding algorithm, we first derive the error-checking equations
Yingxian Zhang   +4 more
doaj   +1 more source

Investigating the Test and Evaluation of GaN Transistors Radiation Resistance in SSPA Amplifier Board in LEO Satellite Payload [PDF]

open access: yesفصلنامه علوم و فناوری فضایی, 2023
With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered ...
Roghieh Karimzadeh Baee   +3 more
doaj   +1 more source

Experimental Demonstration of High-Security and Low-CSPR Single-Sideband Transmission System Based on 3D Lorenz Chaotic Encryption

open access: yesPhotonics
Broadcast-style downlinks (e.g., PONs and satellites) expose physical waveforms despite transport-layer cryptography, motivating physical-layer encryption (PLE).
Chao Yu   +13 more
doaj   +1 more source

Design of Satellite Operations Subsystem Using Dynamic Fault Management Mechanism [PDF]

open access: yesJournal of Astronomy and Space Sciences, 1998
Satellite Operations Subsystem in the Mission Control Element provides real-time monitoring of the satellite status and transmits telecommands to control the satellite during the contact time.
Jaehoon Kim, Heesook Mo, Woonchan Jung
doaj  

Design and Implementation of Hitl Simulator Coupleing Communications Payload and Software Spacecraft Bus [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2003
Engineering qualification model payload for a communications and broadcasting satellite(CBS) was developed by ETRI from May, 2000 to April, 2003. For the purpose of functional test and verification of the payload, a real-time hardware-in-the-loop(HITL ...
In-Jun Kim, Wan-Sik Choi
doaj   +1 more source

NORAD TLE Type Orbit Determination of LEO Satellites Using GPS Navigation Solutions [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2002
NORAD Two Line Elements (TLE) are widely used for the increasing number of small satellite mission operations and analysis. However, due to the irregular periodicity of generation of the NORAD TLE, a new TLE that is independent of NORAD is required.
Chang-Hwa Cho   +4 more
doaj   +1 more source

Africa: cyber-security and its mutual impacts with computerisation, miniaturisation and location-based authentication

open access: yesEAI Endorsed Transactions on Mobile Communications and Applications, 2017
The state of insecurity occasioned by fraudulent practices in Africa has been of concern economically, both at home and abroad. In this paper, we propose ways to mitigate this problem, using Nigeria as a case study.
M.I. Adeka   +8 more
doaj   +1 more source

Communications satellite technology [PDF]

open access: yes, 1964
Communications satellite technology - echo, relay, and syncom ...
Hedrich, A. L.
core   +1 more source

3D‐Printed Hygroscopic Polymer Networks for High‐Humidity Triboelectric Nanogenerators to Wirelessly Power Implantable Electronic Devices‐ A Conceptual Pathway

open access: yesAdvanced Functional Materials, EarlyView.
This work develops 3D‐printable tribopolymer networks that can enhance triboelectric performance under high humidity environments. Polar hydrophilic functional groups and incorporation of zwitterionic monomers promote bound‐water–dominated interfacial polarization thereby increasing electrical outputs.
Linguangze Zhuo   +8 more
wiley   +1 more source

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