Analog Radio-over-Fiber Solutions for 5G Communications in the Beyond-CPRI Era

Current research efforts on 5G RAN strongly focus on pico-cells deployment based on mmWave radio, optical/wireless convergence to support massive-MIMO and a cloud-centric operation of BBUs. Industrial and academic institutions concur that it is of great importance to develop evolutional paradigms that ensure the functional combination of the above technologies into a 5G cellular architecture and its associated ecosystems providing new vertical services. This paper aims to explore the role of Analog RoF solutions moving beyond CPRI implementations for future 5G architectures, highlighting the impact of digital-signal-processing to proposed network implementations. A DSP-assisted IFoF concept to support 60-GHz multi-band wireless connectivity is successfully demonstrated through preliminary experiments showing 12 Gb/s downlink connectivity with centralized processing at BBU side.