Integrating Radio-Over-Fiber Communication System and BOTDR Sensor System

Area of Science:

• Optoelectronics and Communications
• Fiber Optic Sensing Technologies

Background:

• Integrating communication and sensing systems is crucial for cost-effective infrastructure.
• Radio-over-fiber (RoF) and Brillouin optical time-domain reflectometry (BOTDR) are key technologies in modern networks.

Purpose of the Study:

• To demonstrate the first integrated RoF and BOTDR system using a single optical fiber.
• To evaluate the performance of different modulation formats (QPSK, 16-QAM, 64-QAM) within the integrated system.
• To assess the impact of BOTDR sensing on communication signal quality.

Main Methods:

• Implemented an RoF system with OFDM signals modulated by QPSK, 16-QAM, and 64-QAM.
• Utilized a BOTDR system for strain and temperature monitoring over a 25 km fiber link with 5 m spatial resolution.
• Analyzed error vector magnitude (EVM) for different modulation formats under varying BOTDR pump powers.

Main Results:

• Achieved low temperature measurement error (±0.49 °C at 25 km).
• Demonstrated acceptable EVM values within 3GPP requirements using QPSK modulation (3.5% with filter).
• Optimized sensing and data power levels (18 dBm and 10 dBm, respectively) for QPSK.

Conclusions:

• The integrated RoF-BOTDR system is feasible and effective for practical applications.
• Utilizing a single fiber link significantly reduces infrastructure costs.
• The system offers simultaneous high-performance communication and distributed sensing.