Multiband IFoF signal transmission based on DML with local photonic 40 GHz up conversion

Abstract

Multiband data signal transmission using intermediate frequency over fiber (IFoF) is proposed and demonstrated with local photonic millimetre wave (mmW) generation. The proposed scheme is based on a low cost directly-modulated laser (DML) and Mach-Zehnder modulator (MZM) biased at a null point for optical carrier suppression to realize optical frequency multiplication (OFM). Transmission of 4- and 64-quadrature amplitude modulation (QAM) signals providing data rates of 3 and 1.5 Gbps, respectively, over 25 km standard single mode fiber (SSMF) are demonstrated and signals are delivered at 40 GHz to be radiated by the remote radio heads (RRHs). As a proof of concept, also multiband signal of various modulation formats and bandwidths have been transmitted successfully along 25 km fiber link and delivered in the mm W band. Quality signal assessment by error vector magnitude (EVM) measurement at mmW bands is demonstrated and an estimation of the optical sensitivity of the system is provided.