Results 51 to 60 of about 31,082 (236)

Geometric Characterization of LEO–GEO Inter‐Satellite Links for Bidirectional Communications

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Incorporating geosynchronous Earth orbit (GEO) and low Earth orbit (LEO) satellites can extend communication services far beyond the reach of terrestrial infrastructure. A key enabler of such architectures is the establishment of inter‐satellite links (ISLs) between LEOs and GEOs to support bidirectional communications.
Muhammad Furqan, Lingfeng Ye, Yanming Feng   +2 more
wiley   +1 more source

Multi-Functional Antenna Array Assisted MC DS-CDMA Using Downlink Preprocessing Based on Singular Value Decomposition

, 2007
In this contribution we propose and investigate a transmitter preprocessing scheme designed for downlink transmission in multicarrier direct-sequence code-division multiple-access (MC DS-CDMA) systems using multiple base-station antenna arrays, where ...
Xu, C., Chong Xu, Lie-Liang Yang, Hu, B, Yang, L-L, Hanzo, L, Lajos Hanzo, Bin Hu   +7 more
core   +1 more source

Code orthogonality for wideband CDMA systems with multiple transmit antennas [PDF]

, 2007
Code orthogonality is a useful indicator in determining the performance of the synchronous downlink of third generation Universal Mobile Telecommunication System (UMTS) Terrestrial Radio Access systems.
Beach, Mark, Mark A. Beach, Allen, Ben, Hunukumbure, Mythri, Allen, BH, Hunukumbure, MR, Mythri Hunukumbure, Beach, MA, Ben Allen   +8 more
core   +1 more source

Joint Transmitter-Receiver Optimization in the Downlink CDMA Systems

EURASIP Journal on Advances in Signal Processing, 2002
To maximize the downlink code-division multiple access (CDMA) system capacity, we propose to minimize the total transmitted power of the system subject to users′ signal-to-interference ratio (SIR) requirements via designing optimum transmitter ...
Mohammad Saquib, Habibul Islam
doaj   +1 more source

SMTC Configuration and Window Adjustment Strategies for Beam Hopping in NR‐NTN

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Beam hopping is an effective transmission strategy for nonterrestrial networks (NTNs), enabling satellites to allocate limited power and spectrum resources across different geographical regions over time. However, in NR‐based NTN systems, beam hopping complicates synchronization monitoring because synchronization signal block (SSB) arrivals ...
Hee Wook Kim, Kyungrak Lee, Joon Gyu Ryu
wiley   +1 more source

Flexible resource allocation for joint optimization of energy and spectral efficiency in OFDMA multi-cell networks [PDF]

, 2015
The radio resource allocation problem is studied, aiming to jointly optimize the energy efficiency (EE) and spectral efficiency (SE) of downlink OFDMA multi-cell networks.
Jing, Wenpeng, Yang, Shaoshi, Hu, Zhiqun, Lu, Zhaoming, Wen, Xiangming   +4 more
core   +1 more source

Time Series Irradiance Synthesizer for Optical GEO Satellite Downlinks in 5G Networks

Future Internet, 2019
Next generation 5G networks generate a need for broadband, low latency and power efficient backhauling and data-relay services. In this paper, optical satellite communications links, as an integrated component of 5G networks, are studied.
Theodore T. Kapsis, Nikolaos K. Lyras, Charilaos I. Kourogiorgas, Athanasios D. Panagopoulos   +3 more
doaj   +1 more source

Tailoring Model‐Based Systems Engineering for Sub‐100 g PlanarSats: A Power‐First View Stack

Systems Engineering, EarlyView.
ABSTRACT This paper addresses how to apply model‐based systems engineering (MBSE) to ultrasmall planar satellites under severe power and resource constraints. PlanarSats are sub‐100‐gram spacecraft built as single printed‐circuit boards where the same surface must host both electronics and solar cells, so power generation, geometry, and component ...
Mehmet Şevket Uludaǧ, Alim Rüstem Aslan   +1 more
wiley   +1 more source

Cooperative Downlink Multicell Preprocessing Relying on Reduced-Rate Back-Haul Data Exchange [PDF]

, 2011
Different-complexity multicell preprocessing (MCP) schemes employing distributed signal-to-interference leakage-plus-noise ratio (SILNR) precoding techniques are proposed, which require reduced back-haul data exchange in comparison with the conventional ...
Rong Zhang, Zhang, Rong, Hanzo, Lajos, Lajos Hanzo   +3 more
core   +1 more source

The impact of the educational system using immediate feedback in learning the skills of numbers and sending from the bottom volleyball [PDF]

مجلة الرافدين للعلوم الرياضية, 2019
The research aims to uncover the following: 1-The impact of the curriculum using the immediate feedback in learning the skills of numbers and the transmission from the bottom volleyball 2-Differences in the remote selection between the two groups in the ...
Shahla Abdullah
doaj   +1 more source