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Updated: Dec 18, 2025
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Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
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LDPC-Coded CAP with Spatial Diversity for UVLC Systems over Generalized-Gamma Fading Channel
Hongyan Jiang1, Hongbing Qiu1, Ning He1,2
1School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China.
Sensors (Basel, Switzerland)
|June 19, 2020
Summary
Low-density parity-check (LDPC) coded carrierless amplitude and phase (CAP) modulation with spatial diversity effectively combats underwater visible-light communication fading. This technique significantly improves performance, especially under strong turbulence conditions.
Area of Science:
- Optical Communications
- Wireless Communication Systems
- Signal Processing
Background:
- Underwater visible-light communication (UVLC) channels experience fading due to turbulence.
- Existing modulation schemes struggle to maintain reliable communication under varying turbulence intensities.
- Generalized-gamma (GG) distribution accurately models turbulence-induced fading across different regimes.
Purpose of the Study:
- To propose and evaluate a novel LDPC-coded CAP modulation scheme with spatial diversity for UVLC.
- To mitigate the effects of turbulence-induced fading in UVLC systems.
- To analyze the bit-error rate (BER) performance under diverse turbulence conditions.
Main Methods:
- Utilized Generalized-gamma (GG) distribution to model UVLC channel fading.
- Derived an approximated bit-error rate (BER) using the characteristic function (CHF) of GG random variables.
- Implemented and simulated a carrierless amplitude and phase (CAP) modulation system with spatial diversity and equal-gain combining (EGC).
- Integrated low-density parity-check (LDPC) coding for enhanced error correction.
Main Results:
- The proposed LDPC-coded CAP modulation with spatial diversity demonstrates significant mitigation of turbulence-induced fading.
- Performance analysis and simulations validate the effectiveness of the approach across weak and strong turbulence regimes.
- The system shows particular robustness and improved BER under strong turbulence conditions.
Conclusions:
- The combination of LDPC coding and spatial diversity is a highly effective strategy for enhancing UVLC system reliability.
- This approach offers a promising solution for robust underwater optical wireless communication.
- The study validates the theoretical derivations through comprehensive simulations.
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