Journal ArticleDOI
Design and analysis of a reduced phase error digital carrier recovery architecture for high-order quadrature amplitude modulation signals
B. Bornoosh,Abdolreza Nabavi +1 more
TLDR
The authors present an efficient software-aided technique for phase error reduction in CR for high-order QAM, based on the simple and well-known fourth power CR loop, which allows a significant improvement of bandwidth efficiency by increasing the modulation order, at the cost of slight complexity overhead.Abstract:
With increasing order of quadrature amplitude modulation (QAM), the bandwidth efficiency is improved in digital communication. However, in practice, the modulation order is limited, since conventional digital carrier recovery (CR) algorithms give rise to unacceptable phase error. The authors present an efficient software-aided technique for phase error reduction in CR for high-order QAM, based on the simple and well-known fourth power CR loop. Analytical and simulation results indicate that the new technique has several attractive features such as approximate of invariance of phase error improvement over modulation order and low hardware complexity for modulation orders as high as 256-QAM. Experimental results for 64 and 256-QAM illustrate phase error variance of less than −110 dBc/Hz at the frequency offset of 10 kHz, that is, 30 dB reduction of phase error variance or 3 dB increase in system processing gain compared to the conventional fourth power CR loop. This allows a significant improvement of bandwidth efficiency by increasing the modulation order, at the cost of slight complexity overhead.read more
Citations
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Proceedings ArticleDOI
DAC-free generation and 320-km transmission of 11.2-GBd PDM-64QAM using a single I/Q modulator
TL;DR: In this paper, the authors successfully generated 11.2GBd PDM-64QAM using one I/Q modulator driven with eight-level signals synthesized by all binary electrical inputs.
Patent
Carrier recovery method in high order modulation-demodulation
TL;DR: In this paper, the authors proposed a carrier recovery method in high order modulation-demodulation (HOMDM) by inserting an auxiliary sequence and utilizing the correlation of the auxiliary sequence, and the method comprises the steps of extracting clocks, generating timing frames, recovering and compensating the frequency difference of received carriers and transmitted carriers.
Patent
Method and apparatus with improved estimation accuracy and robustness for fine frequency offset estimation in coherent receivers
TL;DR: In this article, a method and system for fine estimation of a local oscillator frequency offset of a received signal at a coherent receiver, by evaluating the probability mass function (PMF) of the signal phase of output symbols at different frequencies, is presented.
Patent
Measuring channel signal to noise metric using constellation data
TL;DR: In this article, the S/N ratio of an input channel carrying a QAM signal is estimated using only the received I and Q components of the modulated QAM input signal itself.
Journal ArticleDOI
Carrier Frequency Estimation with Cyclostationary Signals in Impulsive Noise
TL;DR: Simulation results indicate that the proposed algorithm outperforms the conventional DFT method in impulsive noise.
References
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Application of artificial intelligence to wireless communications
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Proceedings ArticleDOI
Design of carrier recovery algorithm for high-order QAM with large frequency acquisition range
Ki-Yun Kim,Hyung-Jin Choi +1 more
TL;DR: A polarity decision carrier recovery algorithm that is useful for carrier acquisition in high order-QAM (quadrature amplitude modulation) and the RMS (root mean square) phase error performance using the proposed carrier recovery PLL (phase locked loop).
Journal ArticleDOI
Using Times-Four Carrier Recovery in M-QAM Digital Radio Receivers
TL;DR: The results show that the rms phase jitter using the times-four method of carrier recovery, for all but the most severe and improbable fades, could be held to a few degrees, and the damage associated with it should be quite small.