Results 161 to 170 of about 1,345 (198)

Heterodyne video transmission with differentially encoded quadrature phase shift keying

Journal of Lightwave Technology, 1992
Heterodyne transmission experiments of multiple video channels using differentially encoded quadrature phase shift keying (QPSK) are described. Combining the QPSK microwave modulation format with the subcarrier multiplexing technique results in a total of 20 video channels at 50 Mb/s being transmitted on 10 microwave subcarriers.
R. Gross, R. Olshansky
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Digital-analog hybrid optical phase-lock loop for optical quadrature phase-shift keying

Chinese Optics Letters, 2020
We analyze a feasible high-sensitivity homodyne coherent optical receiver for demodulating optical quadrature phase-shift keying (QPSK). A fourth-power phase-lock loop based on a digital look-up table is used. Considering the non-negligible loop delay, we optimize the loop natural frequency. Without error correction coding, a sensitivity of −37 dBm/−35
Shaowen Lu, Yu Zhou, Funan Zhu, Jianfeng Sun, Yan Yang, Ren Zhu, Shengnan Hu, Xiaoxi Zhang, Xiaolei Zhu, Xia Hou, Weibiao Chen   +10 more
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Differential space-time coding with offset quadrature phase-shift keying

IEEE 6th Workshop on Signal Processing Advances in Wireless Communications, 2005., 2005
Differential space-time coding (DSTC) has been well established as a precoding technique that allows maximum likelihood detection of the received symbols without requiring knowledge of channel state information. This type of detection is useful for highly time-varying channels where the resulting cost of channel estimation is high.
A.L. Anderson, J.R. Zeidler, M.A. Jensen
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Quadrature Demodulation of Binary Phase Shift Keyed Signals

IETE Journal of Education, 1988
A quadrature demodulation scheme for Binary Phase Shift Keyed (BPSK) signals is presented. Theory of operation of this demodulator and circuit details for its implementation are given. This technique is useful in systems designed for burst data application requiring fast acquisition such as Time Division Multiple Acces (TDMA), Random Access Descrete ...
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Ultrasonic method for constructing a quadrature phase shift keying system

International Journal of Electronics, 1990
A quadrature phase shift keying (PSK.) system is developed using surface acoustic wave (SAW) devices. A SAW delay device having two or three interdigital transducers (IDT) operates as the key element for the modulation and demodulation of the communication system.
KOHJI TODA, TOSHIO IKEDA, MASAMI FURUSAWA   +2 more
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Multipactor in Microwave Transmission Systems Using Quadrature Phase-Shift Keying

IEEE Transactions on Plasma Science, 2010
A numerical simulation analysis is made of the effect of signal transmission using the quadrature phase-shift keying of a constant-amplitude RF carrier wave on the initiation of multipactor breakdown in RF devices operating under close-to-vacuum conditions.
V Semenov, M Buyanova, D Anderson, M Lisak, R Udiljak, J Puech   +5 more
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Optical channel de-aggregation of quadrature-phase-shift-keying and eight-phase-shift-keying data using mapping onto constellation axes

Optics Letters, 2015
An eight-phase-shift-keying signal is experimentally de-aggregated onto two four-pulse amplitude modulation signals using nonlinear processes in optical elements. Quadrature-phase-shift-keying signals are similarly de-multiplexed into two binary phase shift keying signals by mapping the data points onto the constellation axes.
Morteza, Ziyadi, Amirhossein, Mohajerin-Ariaei, Ahmed, Almaiman, Yinwen, Cao, Mohammad Reza, Chitgarha, Loukas, Paraschis, Moshe, Tur, Carsten, Langrock, Martin M, Fejer, Joseph D, Touch, Alan E, Willner   +10 more
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Offset Generator for Offset Quadrature Phase Shift Keying Modulation

2019
The key concept of this paper is development of an Offset generator architecture for Offset Quadrature Phase Shift Keying (OQPSK). Offset generator designed is embedded into QPSK and generates OQPSK modulation. The symbol pattern which the offset generator generates is such that there is only a maximum phase shift of ±90° between the consecutive ...
Alphyn Stanley, R. K. Sharma
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A 100 MHz MEMS SiBAR phase modulator for quadrature phase shift keying

2012 IEEE International Frequency Control Symposium Proceedings, 2012
A technique is proposed to employ the phase shifting capability of a MEMS resonator to form the basic component of a switchless quadrature phase shift keying (QPSK) scheme. The advantages of such an approach include direct baseband to RF modulation, no generation of intermodulation products since the resonator is operated linearly, and small size, cost,
Logan Sorenson, Farrokh Ayazi
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Design of a Quadrature Differential Chaotic Phase Shift Keying Communication System

2009 International Conference on Networks Security, Wireless Communications and Trusted Computing, 2009
This paper presents a new communication scheme, named quadrature differential chaotic phase shift keying (QDCPSK), which is developed from M-ary phase shift keying, chaotic phase and quadrature chaos shift keying (QCSK). It has not only the advances and characteristics of chaotic communication systems, but also higher efficiency of band usage and ...
Songsheng Zhu, Yinlin Xu, Kuixi Yin
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