Low-cost coherent radio over fibre for dense access networks
Radio over fibre systems have been deployed in some dense urban and indoor environments providing, through distributed antennas, improved coverage, enhanced capacity and flexibility. Digitised radio over fibre is proposed for centralised-/cloud-radio access networks as it provides more predictable and assured performance. However, for future mobile systems, the wireless access speeds are predicted to be in the order of Gb/s. Several GHz of bandwidth per antenna unit will need to be provided, some tens of Gb/s for digitised approaches. The bandwidth requirements may make coherent approaches, now being deployed in core networks, necessary for access networks – but these will need to be low-cost. Several research projects support our radio over fibre activity, particularly the RAPID EU-Japan project (www.rapid5G.eu).