Results 71 to 80 of about 10,809 (212)

QPSK-Modulation Modem Invariant to the Rotation of the Signal Constellation Plane

Electrical, Control and Communication Engineering, 2018
In order to increase the efficiency of dedicated frequency channels, i.e. to increase the specific data transfer rate, multipositional quadrature phase shift keying (QPSK, aka 4-PSK) should be used.
Sadchenko Andrey, Kushnirenko Oleg
doaj   +1 more source

A Massive Grant‐Free Random Access Scheme Based on Spectrum Sensing and Preamble Delay

IET Communications, Volume 20, Issue 1, January/December 2026.
This paper introduces cognitive radio (CR) and preamble delay (PD) to reduce access collisions, together with non‐orthogonal multiple access (NOMA) to improve spectrum efficiency, and thus proposes an efficient CR‐NOMA‐PD‐based massive grant‐free random multiple access scheme.
Jing Zhang, Zhuang‐Zhuang Wei, Yu‐Qi Zhang, Hong‐Xu Gao, Hai‐Tao Zhao, Hong‐Bo Zhu   +5 more
wiley   +1 more source

QPSK regeneration without active phase-locking [PDF]

, 2016
QPSK regeneration without active phase stabilization is investigated in numerical simulations. We propose an improved scheme for phase-locking free QPSK regeneration showing significant improvements in the error vector magnitude of the ...
Røge, Kasper Meldgaard, Kjøller, Niels-Kristian, Galili, Michael, Francesco Da Ros, Michael Galili, Oxenløwe, Leif Katsuo, Leif K. Oxenløwe, Da Ros, Francesco, Kasper Meldgaard Røge, Niels-Kristian Kjøller   +9 more
core   +1 more source

Optimized Silicon QPSK Modulator With 64-Gb/s Modulation Speed

IEEE Photonics Journal, 2015
We demonstrate a compact silicon quadrature phase-shift keying (QPSK) modulator consisting of two nested Mach-Zehnder interferometers with a size of 4.5-mm2. The V11 · L of the modulator is 1.4 V · cm with an insertion loss of 8 dB.
Haike Zhu, Linjie Zhou, Tao Wang, Lei Liu, Chiyan Wong, Yanyang Zhou, Rui Yang, Xinwan Li, Jianping Chen   +8 more
doaj   +1 more source

A Spectral‐Spatial Dual Encoder With Bio‐Inspired Swarm Adaptation for Cognitive Spectrum Sensing Using Real‐World RF Signal Data

IET Communications, Volume 20, Issue 1, January/December 2026.
The proposed model includes a dual‐stream deep learning architecture which has a 1D convolutional neural network (CNN)‐based spectral encoder and a graph convolutional network (GCN)‐based spatial encoder for extracting the frequency‐domain and node‐topology features. Experimental analysis of the proposed model is performed using the Real‐World Wireless
P. Ramakrishnan, C. Kumar, R. Saravana Kumar, Sourav Barua   +3 more
wiley   +1 more source

Modified constant modulus algorithm for polarization-switched QPSK [PDF]

, 2011
A modified constant modulus algorithm (CMA) is presented that allows polarization demultiplexing and equalization of polarizationswitched QPSK. An implementation is suggested that allows easy switching between the traditional and the modified CMA.
Karlsson, Magnus, Henk Wymeersch, Johannisson, Pontus,, Agrell, Erik,, Andrekson, Peter, Karlsson, Magnus,, Agrell, Erik, Erik Agrell, Johannisson, Pontus, Sjödin, Martin E,, Pontus Johannisson, Martin Sjödin, Wymeersch, Henk,, Wymeersch, Henk, Peter A. Andrekson, Sj\uf6din, Martin E, Magnus Karlsson, Sjödin, Martin, Andrekson, Peter,   +18 more
core   +1 more source

Space-time decision feedback equalisation using a minimum bit error rate design for single-input multi-output channels

, 2007
This contribution proposes a minimum bit error rate (MBER) decision feedback equaliser (DFE) designed for single-input multiple-output (SIMO) systems employing a quadrature phase shift keying (QPSK) modulation scheme. It is shown that this MBER design is
Shi, Y., Wolfgang, A., Hanzo, L., Chen, S.   +3 more
core   +1 more source

Ultra-long-haul transmission of 7x42.9Gbit/s PS-QPSK and PM-BPSK [PDF]

, 2011
We report on ultra-long haul transmission of polarization-switched QPSK (PS-QPSK) and polarization-multiplexed BPSK (PM-BPSK) at 42.9Gbit/s per WDM channel.
Killey, RI, Makovejs, S, Millar, DS, Thomsen, BC, Savory, SJ, Lavery, D, Bayvel, P, ,, Behrens, C   +8 more
core   +1 more source

Rotary Valve Control Technology and Simulation Based on Phase Shift Keying Technology

Shiyou jixie, 2019
To further improve the transmission rate and increase the bandwidth utilization during the modulation process of the QPSK and MPSK drilling fluid continuous pressure wave signal, based on the demand of transmission speed and reliability of the wireless ...
Song Xiaojian, Zhang Pengyu, Wang Mingchuan, Zhang Jie, Ma Hongyan, Zhao Yiheng   +5 more
doaj  

Multibeam-based mmWave segmented beamforming array system for high efficiency and secure communication

Engineering Science and Technology, an International Journal
A new mmWave transmitter architecture with multibeam-based segmented beamforming arrays (SBAs) for high-efficiency and secure communication is proposed.
Seung-Won Oh, Woo-Hee Lim, Han Lim Lee
doaj   +1 more source