Results 31 to 40 of about 2,647 (173)

Overcoming the Phase Discontinuity Problem in RIS Optimization: A Robust and Scalable Phase‐Aware Deep Regression Framework via Hybrid CNN–LSTM Architecture

Advanced Intelligent Systems, EarlyView.
The phase discontinuity problem—where the cyclic nature of phase angles causes catastrophic errors near the ±π boundary—is a fundamental obstacle in learning‐based reconfigurable intelligent surface (RIS) optimization. A phase‐aware hybrid CNN–LSTM framework resolves this by decomposing phase predictions into sine–cosine components, mapping circular ...
Seda Savaşçı Şen, Ali Çalhan, Murtaza Cicioğlu, Oğuzhan Demiryürek   +3 more
wiley   +1 more source

Low‐Complexity Hybrid Beamforming for LEO Satellites: Beam Update Rate Analysis and Advanced Adaptive Precoding

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Low Earth Orbit (LEO) satellite constellations offer unprecedented opportunities for global broadband connectivity but pose significant beamforming challenges due to rapid platform motion and stringent onboard hardware constraints. Fully digital architectures, while optimal in theory, remain impractical for satellite payloads, motivating ...
Mohammad Momani, Thomas Delamotte, Andreas Knopp   +2 more
wiley   +1 more source

A Ray-Tracing-Based Single-Site Localization Method for Non-Line-of-Sight Environments

Sensors
Localization accuracy in non-line-of-sight (NLOS) scenarios is often hindered by the complex nature of multipath propagation. Traditional approaches typically focus on NLOS node identification and error mitigation techniques.
Shuo Hu, Lixin Guo, Zhongyu Liu
doaj   +1 more source

A Novel Mobile Target Localization Approach for Complicate Underground Environment in Mixed LOS/NLOS Scenarios

IEEE Access, 2020
Accurate positioning of the shearer remains a challenge for automation of the longwall coal mining process. In this paper, the popular Ultra-wideband (UWB) positioning system that has attracted considerable attention is adopted to obtain the target node ...
Bo Cao, Shibo Wang, Shirong Ge, Xiuze Ma, Wanli Liu   +4 more
doaj   +1 more source

NLOS Identification- and Correction-Focused Fusion of UWB and LiDAR-SLAM Based on Factor Graph Optimization for High-Precision Positioning with Reduced Drift

Remote Sensing, 2022
In this study, we propose a tightly coupled integrated method of ultrawideband (UWB) and light detection and ranging (LiDAR)-based simultaneous localization and mapping (SLAM) for global navigation satellite system (GNSS)-denied environments to achieve ...
Zhijian Chen, Aigong Xu, Xin Sui, Yuting Hao, Cong Zhang, Zhengxu Shi   +5 more
doaj   +1 more source

Analysis of 5.8 GHz Network for Line of Sight (LOS) and Non-Line of Sight (NLOS) in Suburban Environment

International Journal on Advanced Science, Engineering and Information Technology, 2023
This paper presents the findings of radio wave characterization based on the measurement data at 5.8 GHz. The measurement data were collected by a testbed channel, which links with the following scenarios: a single tree, a row of trees, a row of trees and a road, a row of trees, a road, and a building.
Md Idris, Ikha Fadzila, Tan, Kim Geok, Abd Rahman, Noor Ziela, Md Idris, Mohd Haffizzi   +3 more
openaire   +2 more sources

Integrating Image Segmentation and Deep Learning to Improve Radio Frequency Propagation Models

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper proposes a multi‐sensor approach to improve radio frequency (RF) propagation models, which play a key role in the rapidly expanding field of connected vehicle technology. Focusing on the 1‐ to 20‐GHz frequency range, which is critical for both satellite‐to‐vehicle and base station‐to‐vehicle communications, our study introduces a ...
Jonathan Israel, Xavier Boulanger, Vegard Arneson   +2 more
wiley   +1 more source

CNN‐DDQN Spatial Learning for Fractional Frequency Reuse Optimization in 5G Heterogeneous Networks

Engineering Reports, Volume 8, Issue 7, July 2026.
This study proposes a spatially aware DRL framework that uses multichannel network‐state tensors and a lightweight CNN‐DDQN architecture to capture interference patterns and user clustering in 5G heterogeneous networks (HetNets). The model is computationally efficient with only 7361 trainable parameters, achieving 115× faster execution and < 10 ms ...
Christian Onu, Abdulwaheed Musa, Olalekan Ogunbiyi, Lambe Mutalub Adesina, Bilkisu Jimada‐Ojuolape, Monsurat Balogun, Abdurrhaman Ademola Isa, Aliyu Ahmed, Ishmael Zibani, Adamu Murtala Zungeru   +9 more
wiley   +1 more source

CRLBs for WSNs localization in NLOS environment

EURASIP Journal on Wireless Communications and Networking, 2011
Determination of Cramer-Rao lower bound (CRLB) as an optimality criterion for the problem of localization in wireless sensor networks (WSNs) is a very important issue. Currently, CRLBs have been derived for line-of-sight (LOS) situation in WSNs. However,
Wang Peng, Huang Jiyan, Wan Qun
doaj  

Measurement-Based LoS/NLoS Channel Modeling for Hot-Spot Urban Scenarios in UMTS Networks

International Journal of Antennas and Propagation, 2014
A measurement campaign is introduced for modeling radio channels with either line-of-sight (LoS) or non-line-of-sight (NLoS) connection between user equipment (UE) and NodeB (NB) in an operating universal mobile telecommunications system.
Jiajing Chen, Xuefeng Yin, Li Tian, Nan Zhang, Yongyu He, Xiang Cheng, Weiming Duan, Silvia Ruiz Boqué   +7 more
doaj   +1 more source