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[IEEE 2019 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - Dalian, China (2019.9.20-2019.9.22)] 2019 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - Enabling technologies for high-speed LED based underwater visible light communications
摘要： Underwater optical wireless communication (UWOC) is an interesting area need to be explored. In recent years, underwater visible light communication (UVLC) is expected to act as an alternative candidate in next-generation underwater wireless optical communications for the Internet of Underwater Things. The challenge is that the absorption, scattering, diffraction effect and turbulence of water medium, which can bring large attenuation and nonlinearity penalty. Therefore, it needs to apply lots of advanced modulation formats which including orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S OFDM) and carrier-less amplitude and phase modulation (CAP) in UVLC signal system. What’s more, advanced digital processing algorithm such as pre/post equalization, nonlinear compensation and other algorithms based on artificial intelligence are needed. In this paper, we introduce three advanced modulation formats including DFT-S OFDM, OFDM and CAP employing probabilistic shaping for high-speed LED based underwater visible light communication.
关键词： underwater visible light communication,probabilistic shaping,advanced modulation formats
更新于2025-09-16 10:30:52
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Laser Phase Noise Tolerance of Uniform and Probabilistically-shaped QAM Signals for High Spectral Efficiency Systems
摘要： We numerically and experimentally investigate the laser phase noise tolerance of probabilistically shaped (PS) and uniformly shaped (US) quadrature amplitude modulation (QAM) signals. In the simulations, we compare PS-64QAM to US-16QAM, PS-256QAM to US-64QAM, and PS-1024QAM to US-256QAM under the same information rate (IR). We confirm that a sufficient shaping gain is observed with narrow linewidth lasers, whereas degradation of the shaping gain is clearly observed when large phase noise and high order modulation formats are assumed. We also evaluate the pilot ratio dependency of the required optical signal-to-noise ratio at the forward error correction limit and the achievable information rate. Additionally, we compare the performance of two types of CPR updating schemes: updating phase estimation at only the pilot symbol or at all symbols.
关键词： Digital coherent,high order quadrature amplitude modulation,laser phase noise,probabilistic shaping,optical fiber communication
更新于2025-09-16 10:30:52
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Probabilistically Shaped 8-PAM Suitable for Data Centers Communication
摘要： We study non-uniform 8-PAM signaling schemes, based on Maxwell-Boltzmann and exponential source distributions, as candidates suitable for data centers’ communications. We evaluate mutual information of these schemes against corresponding uniform 8-PAM scheme, for different parameters of source distributions. The properly chosen variable parameters for different SNR-regions allows us to closely approach Shannon limit, and to significantly outperform the corresponding uniform counterpart. We demonstrate that LPDC-coded 8-PAM with exponential distribution outperforms the LDPC-coded 8-PAM with uniform distribution of the same achievable information rate by 1.8 dB, and this improvement is comparable to that obtained from mutual information calculations.
关键词： 8-PAM,distribution matching,probabilistic shaping,LDPC coding,exponential distribution
更新于2025-09-09 09:28:46
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Advanced Modulation Techniques for Flexible Optical Transceivers: the Rate/Reach Trade-off
摘要： This tutorial paper reviews advanced modulation techniques that have been proposed in the literature for the implementation of flexible (or reconfigurable) transceivers, which are fundamental building blocks of next-generation software-defined optical networks. Using a common reference multi-span propagation system scenario, the performance of transceivers employing standard quadrature-amplitude modulation with variable-rate forward error correction, probabilistic constellation shaping and time-domain hybrid formats is assessed, highlighting the achievable flexibility in terms of continuous trade-off between transmission rate and distance. The combination of these techniques with sub-carrier multiplexing, which enables an increase of the fiber nonlinearity tolerance thanks to the optimization of the symbol rate per sub-carrier, is also discussed.
关键词： coherent detection,Optical fiber communication,hybrid QAM,flexible optical transceivers,modulation formats,subcarrier multiplexing,probabilistic shaping
更新于2025-09-04 15:30:14