Crest factor minimisation in the frequency domain

DAC Testing Using Impulse SignalsThe Multi-Tone (MT) signal with uniform amplitudes can be used for DAC testing. This paper shows an easier way to generate a MT signal using several impulse signals. The article also analyzes qualities of methods for testing the dynamic parameters of Digital to Analog Converters using an impulse signal. The MT, Damped Sine Wave (DSW) and Sinx/x (SINC) signals will be used as the source for these tests. The Effective Number of Bits (ENOB) and Signal to noise and distortion (SINAD) are evaluated in the frequency domain and they are modified using theCrest Factor(CF) correction and compared with the standard results of the Sine Wave FFT test. The first advantage of the test using an impulse signal is that you need fewer input parameters to create the band signal for testing the DAC. The second one is to reduce the testing time using a band signal in comparison with multiple tests using a single sine wave.

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A recursive optimum frequency domain matrix to reduce crest factor in OFDM systems

2014 IEEE International Conference on Consumer Electronics (ICCE) ◽

10.1109/icce.2014.6775895 ◽

2014 ◽

Cited By ~ 2

Author(s):

Pooria Varahram ◽

Borhanuddin M. Ali ◽

Somayeh Mohammady ◽

Nasri B. Sulaiman

Keyword(s):

Frequency Domain ◽

Ofdm Systems ◽

Crest Factor ◽

Optimum Frequency

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Bayesian Military Impulse Noise Classifier

Volume 9: Mechanical Systems and Control, Parts A, B, and C ◽

10.1115/imece2007-41700 ◽

2007 ◽

Author(s):

Brian Bucci ◽

Jeffrey Vipperman ◽

Amro El-Jaroudi

Keyword(s):

Em Algorithm ◽

Frequency Domain ◽

False Positive ◽

Impulse Noise ◽

Spectral Slope ◽

Crest Factor ◽

Wind Noise ◽

Gaussian Distributions ◽

The Em Algorithm ◽

Damage Claims

Civilian noise complaints and damage claims have created the need for stations to monitor military impulse noise. However, the stations currently in service suffer from numerous false positive detections (due to wind noise) of impulse events and often miss many events of interest. To improve the accuracy of military impulse noise monitoring, an algorithm based upon a Bayesian classifier with inputs of conventional and custom acoustic metrics is proposed. To train and evaluate the noise classifier approximately 1,000 waveforms were field collected. The final Bayesian noise classifier used kurtosis and crest factor and, the frequency domain metrics, spectral slope and weighted square error as inputs. The EM algorithm is utilized to fit multi-Gaussian distributions to the different classes of data. In testing the classifier performed to accuracies of up to 99.6%.

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A crest factor reduction scheme based on recursive optimum frequency domain matrix

IEEE Transactions on Consumer Electronics ◽

10.1109/tce.2014.6851991 ◽

2014 ◽

Vol 60 (2) ◽

pp. 179-183 ◽

Cited By ~ 4

Author(s):

Pooria Varahram ◽

Borhanuddin Ali

Keyword(s):

Frequency Domain ◽

Reduction Scheme ◽

Crest Factor ◽

Optimum Frequency ◽

Crest Factor Reduction

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Research on the Influence of Time-Varying Excitation on Vibration Characteristics of the Spiral Bevel Geared Transmission System with Broken Teeth

Shock and Vibration ◽

10.1155/2021/8880851 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Dalian Yang ◽

Liman Chen ◽

Lingli Jiang ◽

Ping Wang ◽

Jie Tao

Keyword(s):

Frequency Domain ◽

Dynamic Model ◽

Torsional Vibration ◽

Low Frequency ◽

Time Varying ◽

Crest Factor ◽

Time Frequency ◽

Bevel Gears ◽

Spiral Bevel ◽

The Time Domain

Due to heavy and alternating loads of working conditions, spiral bevel gears are prone to broken tooth failures. To solve the problem of vibration characteristic of spiral bevel geared transmission with broken tooth failures that is unknown, this study, considering time-varying mesh stiffness and friction excitation, proposed a torsional vibration dynamic model of spiral bevel geared transmission, which has more simple transmission path and the smaller signal attenuation. First, the time-varying excitations of various broken tooth failure are calculated and introduced into the torsional vibration dynamic model. The vibration response of spiral bevel geared transmission with various broken tooth failures is analysed in the time-frequency domain. Then, the sensitivity of the time-domain statistical index and the frequency domain components to different broken tooth failures are studied. Finally, the correctness of the simulation is verified by experiment. The results show that the crest factor is sensitive to minor tooth failure (10–30%), while kurtosis is sensitive to severe failure (30–60%). With the increase of degrees of broken tooth failure, the energy of the low-frequency band increases obviously.

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