Diversity-reception UWOC system using solar panel array and maximum ratio combining.

Area of Science:

• Optical Engineering
• Wireless Communication
• Photonics

Background:

• Underwater wireless optical communication (UWOC) faces challenges in data rate and detection range.
• Traditional systems often struggle with signal degradation due to water turbidity and movement.

Purpose of the Study:

• To develop and evaluate a lens-free UWOC system utilizing a diversity-reception solar panel array.
• To investigate the performance improvements in data rate, detection range, and signal quality compared to a single detector.
• To assess the system's robustness against underwater environmental factors like bubbles and particulates.

Main Methods:

• Employed a 2x2 solar panel array as a diversity receiver in a lens-free UWOC system.
• Utilized maximum ratio combining (MRC) to merge signals from the array elements.
• Conducted theoretical and experimental studies on solar panel size, photocurrent, voltage, and bandwidth relationships.
• Transmitted a 450-nm blue laser signal over 7 meters in tap water.

Main Results:

• Achieved a data rate of 84 Mbps with a bit error rate (BER) of 2.17 × 10^-3 using a 16-QAM OFDM signal with the solar panel array.
• Demonstrated a 40% data rate improvement compared to a single solar panel (60 Mbps).
• Increased the horizontal detection range from 37 mm (single panel) to 55 mm (array).
• Showed 5.22 dB higher received power sensitivity for the array compared to a single panel under specific conditions (60 Mbps, BER 10^-3).

Conclusions:

• The solar panel array with MRC effectively enhances UWOC system performance, improving both data rate and detection range.
• The diversity reception approach offers superior signal quality and robustness in challenging underwater conditions.
• The proposed system presents a viable solution for high-performance underwater wireless optical communication.