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Abstract-This paper demonstrates a hybrid radio over multimode fibre and free space optics (RoMMF-FSO) system that can be used to extend the transmission range of the 4 th generation longterm evolution (4G-LTE) signal in access networks. A single mode filtering technique (SMFT) is used to enhance 4G-LTE performance. The proposed scheme is evaluated in terms of the system transfer function, laser beam profile, and error vector magnitude (EVM). We show that using SMFT increases the RoMMF-FSO system bandwidth by 2 GHz and improves the received optical power by 13.6 dB. Moreover, the proposed system enhances the EVM by 4%. The measured results show that using a 1 km MMF instead of a 1 km SMF will marginally increase the measured EVM from ~6.6% to ~7% with a 0.2 dB power penalty with respect to the LTE EVM limit of 12.5% as is specified for 16-quadrature amplitude modulation. The proposed system is validated practically under atmospheric turbulence conditions to mimic the outdoor environment. Measured EVM results are verified theoretically through transmitting LTE signals with turbulent using log-normal model. We also show that for a FSO link span of 500 m to meet the EVM target of 12.5% the SNR power penalties are ~2 dB and ~11 dB for σ R 2 of 1.2×10 -4 and 0.1, respectively compared with no turbulence.Index Terms-Free space optics, long term evolution, multimode optical fibres, radio-over-fibre.

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In this paper, we propose a new scheme for the integration between the outdoor and indoor 4G long term evolution networks employing the radio-over free space optics technology for the rural environments applications to reduce the deployment cost. We experimentally characterise the system performance under the atmospheric fading effects including thick fog and a moderate turbulence regime considering 8% error-vectormagnitude as the figure of merit. Keywords: long-term evolution (LTE), radio-over-fibre (RoF), radio-over free space optics (RoFSO), polymer optical fibre, free space optics (FSO).