A Low Phase Noise System for QAM Signal Generation and Transmission with the Carrier of Mm-wave

A microwave-photonic scheme base on an optoelectronic oscillator (OEO) is proposed to achieve the generation and transmission of the QAM signal with the carrier of mm-wave. The QAM signal modulated on a 36GHz carrier is disseminated along a 6 km optical fiber loop. The single sideband (SSB) phase noise of the signal is up to –130 dBc/Hz at 10 kHz offset frequency. The error vector magnitude (EVM) of 16QAM signal and 32QAM signal at remote site is 3.7% and 5.5%.