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Quadrature Amplitude Modulation
2019The Quadrature Modulation Scheme (QUAM) uses sine and cosine orthogonality properties to allow the transmission of two different signals in the same carrier, which occupies a bandwidth that is equivalent to the AM signal. The QUAM modulator can be assembled using two DSB-SC modulators.
Marcelo S. Alencar, Valdemar C. da Rocha
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Weighted-Quadrature-Amplitude Modulation
IEEE Transactions on Electromagnetic Compatibility, 1986A family of weighted-quadrature-amplitude-modulation (WQAM) schemes is introduced and analyzed. One of the staggered WQAM (SWQAM) schemes has low spectral sidelobes, even after hardlimiting, and its performance in an adjacent-channel interference (ACI) environment is superior to that of the QPSK; SQPSK, MSK, and SQORC.
Andy D. Kucar, Kamilo Feher
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Jointly optimized quadrature amplitude modulation
2016 IEEE International Conference on Communications (ICC), 2016Quadrature amplitude modulation has been widely used for high-speed data transmission in modern digital communication systems. In this work, a generalized quadrature amplitude modulation which relaxes the constraint of square lattice is suggested to improve the joint performance of modulation and coding.
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Differential Encoding for Quadrature-Amplitude Modulation
2010 IEEE 71st Vehicular Technology Conference, 2010In this paper, we propose a novel differential encoder for QAM (quadrature-amplitude modulation), by a look-up table instead of a rule. Using a table for differential encoding has the advantages of both low complexity and good error performance. We propose algorithms to construct the table for maximizing the minimum noncoherent distance and minimizing ...
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Polarized light by quadrature amplitude modulation
Optics and Lasers in Engineering, 2013Abstract A new method to create elliptically polarized light based on the quadrature amplitude modulation is proposed. This method begins from an unpolarized light and does not use any classical methods, as for instance those using polarizers and retarders or also by refraction, scattering, dichroism or birefringence effects.
Cruz Meneses-Fabian, Uriel Rivera-Ortega
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Synchrophasor measurement method based on quadrature amplitude modulation
2018 26th Signal Processing and Communications Applications Conference (SIU), 2018Synchrohasor measurement is a common tool to monitor system stability and detect faults in electric power systems and various Phasor Measurement Units (PMUs) have been developed for this purpose. Parameter computation methods of PMUs specifically designed for rapidly time-varying voltage cases caused by nonlinear dynamic loads have been an attractive ...
Ali Gokoglu +2 more
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A Novel Ternary Quadrature Amplitude Modulation
2006 2nd International Conference on Information & Communication Technologies, 2006We propose TQAM (ternary quadrature-amplitude modulation) as a scheme of modulating analog signals to carry ternary digital data. We propose a model for the constellation diagram of the new scheme. Our motivation of thinking about this issue is the fact that the application of multi-value (non-binary) digital signals can provide considerable relief of ...
A.M. Haidar, R. Dernaika, F. Shibani
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Fundamentals of Quadrature Amplitude Modulation
1995Quadrature amplitude modulation (QAM) is a widely used method for transmitting digital data over bandpass channels. It can be viewed as a generalization of PAM to bandpass channels. All current telephone line modems based on the ITU-T V series recommendations for transmission at rates of 2400 bps or more use QAM or include it as an option.
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Quadrature Null Effect in Amplitude Modulation
International Journal of Technology, 2017Quadrature null effect (QNE) is a phenomenon in amplitude modulation (AM) demodulator circuit arise if carrier signal generated from local oscillator is not synchronized in phase with input signal. Our main motive is to synchronize phase in this effect by various synchronizing techniques so as to reconstruct input modulated signal completely, are ...
Archi Jain, Divanshu Chhabra
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