A Photonic Pre-Distortion Technique for RF Self-Interference Cancellation

We propose a photonic pre-distortion technique to perform self-interference cancellation for radio-frequency signals. The intensity-modulation direct-detection system is modified by adding a Mach-Zehnder modulator and an optical delay line. With a prior knowledge of the interferer, the optical carrier is pre-distorted before modulated by the received corrupted signal. The delay and amplitude adjustments in our system are optically implemented. Experimental results show that the system achieves 32.6 dB of cancellation across 100-MHz bandwidth and 57 dB of cancellation for 10-KHz narrowband interference.