High fidelity underwater wireless optical communication with a phase-conjugated frame structure

Area of Science:

• Optical Communications
• Signal Processing

Background:

• Phase noise is a critical factor affecting performance in underwater wireless optical communication systems.
• Existing methods for mitigating noise in m-quadrature amplitude modulation-orthogonal frequency division multiplexing (m-QAM-OFDM) have limitations.

Purpose of the Study:

• To analyze phase noise influence factors and theoretically derive its principle.
• To propose a novel frame structure for m-QAM-OFDM in underwater wireless optical communication to enhance performance.

Main Methods:

• Detailed analysis and experimental verification of phase noise influence factors.
• Development of a new frame structure incorporating phase-conjugated signals for m-QAM-OFDM.
• Experimental demonstration of the proposed frame structure in various underwater scenarios.

Main Results:

• Significant improvement in bit error rate (BER) performance.
• Substantial increase in transmission capacity compared to traditional phase-conjugated methods.
• Effective noise suppression achieved through simple superposition of phase-conjugated symbols.

Conclusions:

• The proposed frame structure offers a robust and simple solution for underwater wireless optical communication.
• It provides a favorable compromise between transmission capacity and communication distance.
• This method enhances the feasibility and efficiency of m-QAM-OFDM in underwater environments.