All-Fiber Full-Duplex Multimode Wavelength-Division-Multiplexing Network for Radio-Over-Multimode-Fiber Distribution of Broadband Wireless Services

We present a full-duplex multimode wavelength-division-multiplexing ring network for the distribution of broadband wireless services. It successfully combines the use of all-fiber wavelength selecting multimode add/drop multiplexing nodes with a radio-over-multimode-fiber technique that is robust against modal dispersion impairments in multimode fiber links, and allows a reliable delivery of wireless services beyond 5 GHz. The multimode add/drop multiplexing nodes are built with commercially available narrowband multimode fiber Bragg gratings. The feasibility of the proposal is experimentally investigated with the distribution of 120-Mb/s 64 quadrature amplitude modulation radio signals at 24 GHz over a 4.4-km-long multimode fiber ring with multimode add/drop multiplexing nodes, achieving error vector magnitude values below 4.5%.

I. Introduction

For the sake of reducing infrastructure cost and antenna site complexity in the access architecture of the emerging high-capacity wireless access networks, the benefits of a transparent radio-over-fiber distribution antenna system—which enables the consolidation of the radio access control, generation and processing of radio signals at a centralized control station, and their transparent distribution to simplified antenna stations via optical fiber—has been long recognized [1], [2].