Design and Integration of Fiber Fronthaul with Soft PHY for OAI-BASED RAN

Abstract

For high-speed communications need, Fronthaul, a new mobile architecture related to RAN-based networks, has been widely used in 4G/5G mobile network. Compared with the traditional architecture of the baseband station, Fronthaul is divided into baseband unit (BBU) and remote radio head (RRH). Due to the separation, the interface between BBU and RRH requires more effort to handle the data rate transmission. In this paper, we propose the fiber Fronthaul to achieve the high bandwidth requirement. The BBU includes the SoftPHY OAI running on Intel 17-6700 CPU and the data collector implemented by Xilinx VC707. The RRH is implemented by Xilinx ZC706. And the RF front-end is implemented by Analog Devices AD-FMCOMMSS-EBZ. The interface between the SoftPHY OAI and the data collector is PCIe, and the interface between the data collector and the RRH is optical fiber. It is important that we design the synchronization scheme to synchronize and calibrate the real-time clock (RTC) of different RRH. Therefore, the proposed fiber Fronthaul with SoftPHY OAI can achieve the long distance, stability and high speed transmission.