Seamless Fiber-Wireless System in W-Band Using Optical Phase Modulation and Self-Homodyne Receiver

We propose and demonstrate a seamless fiber-wireless system in the W-band using a simple transmitter, antenna site, and radio receiver. The transmitter utilizes an optical phase modulator instead of an optical in-phase/quadrature modulator for data modulation. A high-output optical-to-radio converter is fabricated and used for radio signal generation at the antenna site. The receiver employs a self-homodyne detector (SHD) that does not require a separate local oscillator source to receive and down-convert the signal to the microwave band. For a proof-of-concept demonstration, we successfully transmitted a high-order quadrature amplitude modulation orthogonal frequency-division multiplexing signal with a bandwidth of up to 4 GHz over the system. The performance of the signal transmission over the system using an envelope detector was also evaluated. Owing to its better received sensitivity, the SHD receiver exhibited better performance. The proposed system can facilitate the deployment of seamless access networks in high-frequency bands in future mobile networks.