Results 41 to 50 of about 4,863,781 (309)

FREQUENCY HOPPING SPREAD SPECTRUM TRANSMITTER DENGAN PSEUDO NOISE CODE

Techne, 2012
Dalam tulisan ini dirancang sebuah alat sistem telekomunikasi data digital dengan teknik Frequency Hopping Spread Spectrum dengan menggunakan Pseudo Noise Code.
Budihardja Murtianta
doaj  

Fast carrier recovery in FHSS systems with DDS based Costas loop [PDF]

Electronics, 2015
Owing to fast change of carrier frequency, the usage of coherent demodulation methods in Frequency-Hopping Spread Spectrum (FHSS) communication systems is limited by the coherent state acquisition performed by the local oscillator.
Slavko Šajić
doaj   +1 more source

2D Co‐Assembly of Solid Acids Enables Stable Superprotonic Conduction Above 260°C

Advanced Functional Materials, EarlyView.
A two‐dimensional co‐assembly strategy integrates antimony phosphate and phosphotungstic acid nanosheets into free‐standing inorganic lamellar membranes with confined acid–acid interfaces. The resulting interfacial hydrogen‐bond network enables anhydrous proton conductivity exceeding 0.1 S cm−1 at 260°C and supports stable high‐temperature fuel‐cell ...
Qiuning Li, Kaiqiang He, Dehua Dong, Fanmengjing Wang, Xiangcheng Liu, Zhikao Li, Jacek J. Jasieniak, Paul A. Webley, Huanting Wang   +8 more
wiley   +1 more source

Overlapping M-ary Frequency Shift Keying Spread-Spectrum Multiple-Access Systems using Random Signature Sequences

, 1999
In this paper, a multiple-access spread-spectrum communication system using binary frequency shift keying (BFSK) or M-ary frequency shift keying (MFSK) and noncoherent demodulation is considered.
Yang, L-L., Hanzo, L.
core   +1 more source

Balancing Hydrophobicity and Hydrophilicity: Dual Filler‐Engineered Proton Exchange Membranes for Durable, High‐Power Fuel Cells

Advanced Functional Materials, EarlyView.
Polarity‐matched Zr–MOFs program Nafion's nanoscale morphology during solution casting. Hydrophilic UiO‐66 preserves hydrated pathways, while hydrophobic UiO‐67 increases the proton hopping sites by densifying ionic clusters. Combining both fillers yields a membrane that delivers 176 mS cm−1 conductivity, reaches 1.46 W cm−2 under 200 kPa, and triples ...
Yonghwi Cho, Yunseong Ji, Minkyu Choi, Junsu Kim, Yejin Kim, Su Jeong Lee, Wooyoung Choi, Choong Hoo Lee, Ju Yeon Kim, Ohchan Kwon, Hanim Kim, Du Yeol Ryu, Ki Chul Kim, Dae Woo Kim   +13 more
wiley   +1 more source

Construction of secure adaptive frequency hopping sequence sets based on AES algorithm

IET Communications
Communication security has become particularly crucial with the rapid development of the Internet of Things (IoT). Frequency hopping spread spectrum (FHSS) technology, a prevalent method in wireless communication, has a wide range of applications in the ...
Dongpo Song, Peng Wei, Yongming Fu, Shilian Wang   +3 more
doaj   +1 more source

New Extension Interleaved Constructions of Optimal Frequency Hopping Sequence Sets With Low Hit Zone

IEEE Access, 2019
In this paper, a designated interleaved structure of constructing optimal frequency-hopping sequence (FHS) sets with low hit zone (LHZ) is presented based on the Cartesian product.
Xian-Hua Niu, Lu Han, Xing Liu
doaj   +1 more source

Electrochemical Pathways for Nitrate Conversion to Ammonia: From Environmental Challenges to Ammonia Economy

Advanced Functional Materials, EarlyView.
This perspective presents recent advances in electrocatalytic nitrate reduction, focusing on reaction mechanisms, catalyst design, and electrolyzer configurations. Key challenges in selectivity, stability, and practical wastewater treatment are highlighted, while future directions for advancing sustainable ammonia synthesis and nitrate remediation are ...
Xintong Li, Yunpeng Zuo, Xiaoran Zhang, Jieqiong Shan, Kenneth Mei Yee Leung, Bin Liu, Peter Strasser, Adrian Fisher, Zonglong Zhu, Xin Wang   +9 more
wiley   +1 more source

Multistage, Self‐Sensing Artificial Muscles With Coordination From Liquid Crystal Elastomer‐Graphene Composite Fibers

Advanced Functional Materials, EarlyView.
Inspired by skeletal muscles’ precision and endurance, CoilLCE integrates a self‐sensing liquid crystal elastomer/graphene artificial muscle with an embedded Joule‐heating copper coil, enabling closed‐loop multistage actuation with programmable intermediate states (strain accuracy of 2%), and antagonistic coordination (32% total strain). These features
Ziyun Zhang, Xuelin Wu, Yinding Chi, Qingya Huang, Yaoye Hong, Antonio Proctor Martinez, Jingxian Wu, Bingzhi He, Cynthia Sung, Shu Yang   +9 more
wiley   +1 more source

Residue Number System Assisted Fast Frequency-Hopped Synchronous Ultra-Wideband Spread-Spectrum Multiple-Access: A Design Alternative to Impulse Radio

, 2002
Ultra-wideband (UWB) systems having a bandwidth on the order of gigahertz have recently received wide attention both in the U.S. and in Europe. The family of UWB systems may communicate either by generating ultra-wideband signals or with the aid of ...
Yang, L-L, Hanzo, L.
core   +1 more source