4 bits/symbol Phase and Amplitude Modulation on a Single Discrete Eigenvalue for Transmissions based on Nonlinear Fourier Transform

Author(s):  
Tao Gui ◽  
Shun Ka Lo ◽  
Xian Zhou ◽  
Chao Lu ◽  
Alan Pak Tao Lau ◽  
...  
Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1131
Author(s):  
Benedikt Leible ◽  
Daniel Plabst ◽  
Norbert Hanik

In this paper, data-transmission using the nonlinear Fourier transform for jointly modulated discrete and continuous spectra is investigated. A recent method for purely discrete eigenvalue removal at the detector is extended to signals with additional continuous spectral support. At first, the eigenvalues are sequentially detected and removed from the jointly modulated received signal. After each successful removal, the time-support of the resulting signal for the next iteration can be narrowed, until all eigenvalues are removed. The resulting truncated signal, ideally containing only continuous spectral components, is then recovered by a standard NFT algorithm. Numerical simulations without a fiber channel show that, for jointly modulated discrete and continuous spectra, the mean-squared error between transmitted and received eigenvalues can be reduced using the eigenvalue removal approach, when compared to state-of-the-art detection methods. Additionally, the computational complexity for detection of both spectral components can be decreased when, by the choice of the modulated eigenvalues, the time-support after each removal step can be reduced. Numerical simulations are also carried out for transmission over a Raman-amplified, lossy SSMF channel. The mutual information is approximated and the eigenvalue removal method is shown to result in achievable rate improvements.


2021 ◽  
Author(s):  
Yutian Wang ◽  
Songnian Fu ◽  
Chi Zhang ◽  
Xiahui Tang ◽  
Jian Kong ◽  
...  

2015 ◽  
Vol 45 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Svetlin Stoyanov

Abstract An analytical solution for a specific case of the forced Duffing oscillator is proposed. The excitation force contains two harmonics with significant difference frequencies. This case corresponds to a presence of a defect in the machinery and is in the art of the machinery vibration diagnostics. The results obtained show an amplitude modulation. Therefore, the presence of an amplitude modulation in the vibration signal may be used as an indicator for a malfunction. Analytical solution derived clarifies how the amplitude modulation occurs. Also, a numerical solution is realized and compared with the analytical one. For this, the Duffing equation is solved numerically and then, the spectrograms of vibrations are obtained through a Discrete-time Fourier Transform.


Sign in / Sign up

Export Citation Format

Share Document