Abstract
To cope with the surging growth of internet mobile traffic and wireless services, optical millimeter wave (MMW) is a key technology to promote radio-frequency-over-fiber (RFoF) to become a promising solution for the next generation 5G high-speed access networks. Thus most wireless operators focus on mobile fronthaul (MFH) network architecture featuring a centralized controlling and managing with optimized service quality. In such MFH networks one major challenge is to seamlessly integrate the abundant newly deployed remote radio head (RRH) with the existing central offices (COs) for hybrid optical-wireless MMW service in a cost-effective manner. However, devices with high bandwidth seem to be the only approach to transmit and receive the optical MMW signal at MFH uplink in 5G hybrid fiber-wireless systems. Unfortunately, many sticky problems arise from high bandwidth devices in receivers, such as limited noise preventions and huge construction expenditure. To resolve this dilemma, we propose a novel solution to appropriately transmit and receive MMW signals featuring with low bandwidth components in this work. We firstly design a receiver architecture to receive 30 GHz MMW uplink in COs but with beneath 12 GHz bandwidth devices mainly based on an optical frequency conversion, and secondly we utilize two different nonlinear dynamic patterns of a 10 GHz semiconductor laser, period-1 and stable locking, to generate uplink MMW signals instead of direct modulation via high bandwidth modulator. Hence, the employed components are all with a bandwidth requirement below 12 GHz, which leads to an effective cost reduction and relieve system complexity. In this work, a back-to-back and a 25-km single mode fiber transmission with 0.3-m, 1-m and 1.5-m wireless transmission scenarios are experimentally demonstrated with various modulation formats.