'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
In this paper we propose multicore fiber (MCF) as the medium to transport the different
signals associated with various wireless applications (ranging from access to fronthauling and backhauling)
from the baseband unit (BBU) to the cell-site. Using 1 km of a 7-core MCF, we simultaneously transmit
fronthaul and backhaul signals from the BBU to the cell site, where they are converted to carrier frequencies
in the mm-wave and sub-THz band, respectively. The backhaul is evaluated with a 12.5 GBd 16-quadrature
amplitude modulation (QAM) signal, whereas the fronthaul is evaluated with a 7 Gbit/s on-off keying (OOK)
signal carrying 14 LTE-compatible channels. The fronthaul signal is generated with a novel compression
technique that achieves an efficiency 3-times higher than the one obtained with the common public radio
interface (CPRI) protocol. Optical heterodyining is implemented at the cell site for optical-to-RF conversion.
The local oscillator (LO) signal required for optical heterodyning is transmitted in a dedicated core,
reducing the system complexity and enabling its straight-forward reuse for uplink (UL) transmission. The
experimental demonstration includes the simultaneous full-duplex transmission of both the fronthaul and
backhaul signals, using 6 cores of the MCF at the same time and achieving a gross data rate of 57 Gbit/s
