Results 151 to 160 of about 3,362 (185)

1024-QAM and 256-QAM Coded Modems for Microwave and Cable System Applications

IEEE Journal on Selected Areas in Communications, 1987
Low redundancy FEC coded 1024-QAM modems, staggered 1024-QAM, and 256-QAM modems for spectrally efficient (up to 8.84 bits/s/Hz) microwave and cable systems applications are described. Such a high spectral efficiency is required for CEPT-1 (2.048 Mbit/s) rate digital transmission in a single analog supergroup (SG` band as well as for other emerging ...
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NLA-QAM: A Method for Generating High-Power QAM Signals Through Nonlinear Amplification

IEEE Transactions on Communications, 1982
A generalized technique for generating quadrature amplitude modulated (QAM) signals that permits nonlinear amplification is presented. With this technique a high-power 2^{2n} -state QAM signal is generated by combining n unfiltered, nonlinear amplified, QPSK signals, n being a positive integer.
Douglas H. Morais, Kamilo Feher
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Statistics of companding noise for QAM transmission

IEEE Transactions on Communications, 1996
In modern voiceband data communication, the received signal is subject to nonlinear quantization noise due to companding. Under certain conditions, this quantization noise may become dominant and cause serious degradation in performance. In order to design better signal constellations for this environment, it is of interest to characterize this noise ...
Jeffrey Davidson, Irving Kalet
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Capacity/modulation tradeoffs in going from 64 QAM to 256 QAM

IEEE International Conference on Communications, Including Supercomm Technical Sessions, 1990
Summary form only given. Increasing the modulation complexity permits significant improvements in bandwidth efficiency. However, the higher level modulation schemes must include additional countermeasures to minimize increased susceptibility to dispersion, loss of threshold, further transmitter power backoff, and increased interference susceptibility. >
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Corrections to "On the QAM modulation"

IEEE Communications Letters, 2002
Elvio César Giraudo, Renato Baldini Filho, Rege Romeu Scarabucci   +2 more
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On the Computation of 16-QAM and 64-QAM Performance in Rayleigh-Fading Channels [PDF]

, 1992
SUMMARY Quadrature Amplitude Modulation (QAM) schemes are attractive in terms of bandwidth efficiency and offer a number of subchannels with different integrities via both Gaussian and Rayleigh-fading channels, Specifically, the 16-QAM phasor constellation has two, while the 64-QAM possesses three such subchannels, which become dramatically different ...
Fortune, P.M., Hanzo, L., Steele, R.
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Understanding the error performance of 16-QAM, 32-QAM, 64-QAM, 256-QAM

2020
Trinder, Julian, M A Ceng
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A Multi-layer UEP Scheme for VOLTE Transmission Using QAM and S-QAM

Wireless Personal Communications, 2022
Prateema Ragpot, Tulsi Pawan Fowdur, Krishnaraj Madhavjee Sunjiv Soyjaudah   +2 more
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Basic QAM Techniques

2011
This chapter contains sections titled: Constellations for Gaussian Channels General Pulse Shaping Techniques Methods of Generating QAM Methods of Detecting QAM Signals Linearisation of Power Amplifiers Non-differential Coding for Square QAM Differential Coding for Square QAM ...
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Modulátor QAM

Náplní práce je zvážit možné způsoby realizací vícestavových modulátorů pro vytvoření laboratorního přípravku. Přípravek bude názorně ukazovat signály, které se podílí na vytváření modulací QAM. Návrh přípravku v práci obsahuje teoretický návrh schématu i samotné vyhotovení funkčního prototypu.
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