Integrated sensing and communication in an optical fibre

Area of Science:

• Optical Communications
• Distributed Sensing
• Signal Processing

Background:

• Ubiquitous optical fibre networks offer potential for intelligent functionalities like urban imaging and pipeline monitoring.
• Integrating communication and sensing can enhance network capabilities and performance.

Purpose of the Study:

• To demonstrate a scheme for integrated sensing and communication in optical fibre (ISAC-OF) using a single wavelength channel.
• To simultaneously achieve high-speed data transmission and distributed vibration sensing.

Main Methods:

• Generation of periodic linear frequency modulation (LFM) light for optical carrier and sensing probe.
• Utilizing Pulse Amplitude Modulation 4 (PAM4) for data transmission and phase-sensitive optical time-domain reflectometry (Φ-OTDR) for sensing.
• Detection and demodulation of forward PAM4 signals and Rayleigh backscattering signals after 24.5 km fibre transmission.

Main Results:

• Achieved ~1.3 dB transmission performance improvement and 7 dB launching power enhancement at 56 Gbit/s compared to conventional PAM4.
• Obtained 4 m spatial resolution, 4.32 nε/√(Hz) strain resolution, and >21 kHz frequency response for vibration sensing.
• Demonstrated simultaneous data transmission and distributed vibration sensing on the same wavelength channel.

Conclusions:

• The ISAC-OF scheme enhances intelligent functionality and transmission performance of optical fibre communication systems.
• This integrated approach offers a novel pathway for leveraging fibre-optic networks for both data transmission and status sensing.
• Shared spectrum utilization in communication and sensing may enable measurement of non-linear parameters, benefiting data transmission.