Full-Duplex 60GHz Radio over Fiber Link with 10Gb/s 16-QAM Downstream and 2.5Gb/s Upstream without Optical Source in Base Station

摘要

A full-duplex radio over fiber (RoF) link scheme with 16 quadrature amplitude modulation (16-QAM) l0Gb/s downstream and 16-QAM 2.5Gb/s upstream signals is proposed. In the downlink, the 60GHz dual-tone optical mm-wave signal carrier is generated by the 15GHz local oscillator via a Mach-Zehnder modulator with frequency quadrupling,and the 16-QAM 5GHz IF signal is up-converted to 65GHz by modulating it on one of the two tones with single sideband (SSB) modulation at central station. At the remote base station, the 65GHz SSB optical mm-wave signal is detected by a high-speed photodiode (PD). After the 60GHz uplink dual-tone optical mm-wave carrier is abstracted by properly filtering, the up-link 63GHz mm-wave signal is modulated on it to down-convert to the 3GHz SSB optical IF signal. Since both the down-and up-link optical mm-wave signals have the SSB spectra with the signal modulated on one of two tones, they suffer little from the fiber dispersion. The results show that the bidirectional signals have good performance even after transmitted over 30km standard single mode fiber.