1-bit Digital Radio-over-Fiber System with Hybrid Architecture for 40-GHz Band

This paper presents a 1-bit digital radio-over-fiber (RoF) system for both downlink and uplink for the first time in the world. The system adopts hybrid architecture with outphasing modulation at IF for downlink and ΔΣ modulation at BB for uplink, allowing for simple system architecture and relaxed linearity requirements for optical devices. The prototype has succeeded in wireless communication using 5G NR signal with 100-MHz bandwidth at 40-GHz band, achieving the EVM of 3.94% and the ACLR of −30 dBc for downlink, and the SNR of 30 dB at baseband for uplink in the over-the-air measurements.