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This article presents an experimental demonstration of a high-capacity millimeter-wave 5G NR signal transmission with analog radio-over-fiber (ARoF) fronthaul over multi-core fiber and full real-time processing. The demonstration validates the core of the blueSPACE fronthaul architecture which combines ARoF fronthaul with space division multiplexing in the optical distribution network to alleviate the fronthaul capacity bottleneck and maintain a centralized radio access network with fully centralized signal processing. The introduction of optical beamforming in the blueSPACE architecture brings true multi-beam transmission and enables full spatial control over the RF signal. The proposed ARoF architecture features a transmitter that generates the ARoF signal and an optical signal carrying a reference local oscillator employed for downconversion at the remote unit from a single RF reference at the central office. A space division multiplexing based radio access network with multi-core fibre allows parallel transport of the uplink ARoF signal and reference local oscillator at the same wavelength over separate cores. A complete description of the real-time signal processing and experimental setup is provided and system performance is evaluated. Transmission of an 800 MHz wide extended 5G NR fronthaul signal over a 7-core fibre is shown with full real-time signal processing, achieving 1.4 Gbit/s with a bit error rate < 3.8 × 10 - 3 and thus below the limit for hard-decision forward error correction with 7% overhead. [ABSTRACT FROM AUTHOR]

Radio-over-Fiber (RoF)-based cellular backhauling consitutes a promising solution to realize a cost-effective evolution of radio access networks towards higher radio-cells densification. In this paper, we recall the main characteristics of an innovative cellular backhauling all-optical network architecture called Generic Radio-over-Fiber Access Network (GeRoFAN) aiming to federate 4G system radio cells. However, the transport of multiple radio channels over an analog RoF link is subject to optical crosstalk and intermodulation distortions causing a decrease of the wireless system capacity. Supported by an analytical modeling of the relevant optical transmission limitations, we propose an impairment-aware radio cellular backhauling strategy for GeRoFAN able to maximize the radio cellular capacity while achieving an efficient use of optical resources. This optimization problem is solved through Pareto-based Genetic Optimization (PaGeO), a multi-objective meta-heuristic based on evolutionary algorithms and exploiting the concept of Pareto front. Numerical results indicate that PaGeO, applied to LTE cellular system, outperforms alternative backhauling strategies by achieving an excellent compromise between preserving the radio capacity of the system and the number of required optical channels. We also highlight how the optimal backhauling strategy calculated using PaGeO enables GeRoFAN to take full benefit from overlaying several radio channels per cell site. [ABSTRACT FROM AUTHOR]