Spectrally efficient optical CDMA system based on chromatic dispersion for phase coding of individual spectral lines in the time domain

2009 ◽  
Author(s):  
Santiago Tainta ◽  
Waldimar Amaya ◽  
Maria J. Erro ◽  
Maria J. Garde ◽  
Raimundo García-Olcina ◽  
...  
Keyword(s):  
Time Domain ◽  
Chromatic Dispersion ◽  
Spectral Lines ◽  
Optical Cdma ◽  
Cdma System ◽  
Phase Coding ◽  
Spectrally Efficient ◽  
The Time Domain

Spectrally Efficient Phase Encoded Optical CDMA System in Time Domain

2008 ◽  
Author(s):  
Santiago Tainta ◽  
Maria J. Erro ◽  
Maria J. Garde ◽  
Miguel A. Muriel
Keyword(s):  
Time Domain ◽  
Optical Cdma ◽  
Cdma System ◽  
Spectrally Efficient

Construction of a two-dimensional-VWOOC based on time domain/frequency domain optical CDMA system

2020 ◽  
Vol 16 (5) ◽  
pp. 384-389
Author(s):  
Zhuo Lu ◽  
Ye Lu ◽  
Chuan-qi Li ◽  
Peng Zhou
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Optical Cdma ◽  
Cdma System ◽  
Two Dimensional

scholarly journals Suppressing of Power Line Artifact From Electroencephalogram Measurements Using Sparsity in Frequency Domain

2021 ◽  
Vol 15 ◽  
Author(s):  
Jin-Lin Tan ◽  
Zhi-Feng Liang ◽  
Rui Zhang ◽  
You-Qiang Dong ◽  
Guang-Hui Li ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Disease Diagnosis ◽  
Power Line ◽  
Spectral Lines ◽  
Rectangular Window ◽  
Parameter Estimations ◽  
Novel Approach ◽  
The Time Domain ◽  
Spectrum Correction

Electroencephalogram (EEG) plays an important role in brain disease diagnosis and research of brain-computer interface (BCI). However, the measurements of EEG are often exposed to strong interference of power line artifact (PLA). Digital notch filters (DNFs) can be applied to remove the PLA effectively, but it also results in severe signal distortions in the time domain. To address this problem, spectrum correction (SC) based methods can be utilized. These methods estimate harmonic parameters of the PLA such that compensation signals are produced to remove the noise. In order to ensure high accuracy during harmonic parameter estimations, a novel approach is proposed in this paper. This novel approach is based on the combination of sparse representation (SR) and SC. It can deeply mine the information of PLA in the frequency domain. Firstly, a ratio-based spectrum correction (RBSC) using rectangular window is employed to make rough estimation of the harmonic parameters of PLA. Secondly, the two spectral line closest to the estimated frequency are calculated. Thirdly, the two spectral lines with high amplitudes can be utilized as input of RBSC to make finer estimations of the harmonic parameters. Finally, a compensation signal, based on the extracted harmonic parameters, is generated to suppress PLA. Numerical simulations and actual EEG signals with PLA were used to evaluate the effectiveness of the improved approach. It is verified that this approach can effectively suppress the PLA without distorting the time-domain waveform of the EEG signal.

Sign in / Sign up

Export Citation Format

Share Document