Performance analysis of an optical self-interference cancellation system with a directly modulated laser-based...

Area of Science:

• Optical communications
• Signal processing

Background:

• Optical self-interference cancellation (OSIC) is crucial for advanced communication systems.
• Understanding performance limitations is key to optimizing OSIC systems.

Purpose of the Study:

• To theoretically analyze the cancellation bandwidth and depth of OSIC systems.
• To investigate the impact of delay deviation on bandwidth and compare OSIC with electrical schemes.
• To experimentally validate the OSIC cancellation model using a directly modulated laser (DML).

Main Methods:

• Theoretical analysis of OSIC performance indices: cancellation bandwidth and depth.
• Investigation of delay deviation as a bandwidth determinant.
• Experimental verification using a DML-based OSIC system with antennas.
• Orthogonal frequency division multiplexing (OFDM) signal testing.

Main Results:

• Delay deviation identified as the primary factor limiting cancellation bandwidth.
• Theoretical proof of OSIC's bandwidth advantage over electrical systems.
• Experimental demonstration of 22 dB and 25 dB broadband cancellation at 900 MHz and 2.4 GHz, respectively.
• Successful in-band full-duplex transmission with self-interference suppression and signal recovery.

Conclusions:

• The developed cancellation model accurately predicts OSIC system performance.
• OSIC systems offer significant advantages in bandwidth and cancellation depth for full-duplex communication.
• DML-based OSIC systems are viable for high-performance, interference-free wireless communication.