Novel cost-effective PON-to-RoF photonic bridge for multigigabit access networks

Telecommunication operators are investing significant resources in developing passive optical networks (PONs) to meet the increasing capacity requirements. Therefore, wireless transmission has become the bottleneck for the wireless broadband internet access due to the spectrum saturation. This issue can be solved taking advantage of the huge portions of unused spectrum at high-microwave / millimeter-wave (mm-wave) bands, but their generation is power consuming. Radio over fiber (RoF) is a cost-efficient solution for the distribution of high-frequency broadband signals to remote base stations. We present a novel photonic PON-to-RoF bridge based on heterodyning a PON signal with an unmodulated tone generated by an independent laser. The proposed scheme is transparent to modulation format and can generate RF signals in the entire microwave band. The feasibility of the bridge is experimentally shown converting a 2-Gbps orthogonal frequency division multiplexing PON signal using inexepensive distributed feedback lasers, whose phase noise is cancelled employing an envelope detection based mobile terminal.