Expanding the mobile radio coverage of multi-terminal serial optical link using wavelength division muitiplexing

This paper proposes a new distributed radio access system for mobile phones that uses optical fiber RF transmission. This system features a tree-type fiber link construction to expand the coverage of MSOL-a previously proposed multi-terminal serial optical link scheme. Wavelength division multiplexing (WDM) is newly applied to achieve the tree-type construction, in which multiple numbers of MSOL sub-links (branches) spread from the main link (trunk). The effect of wavelength dispersion upon the expanding capability is analyzed. An experimental system having three sub-links (using 1.3 μm, 1.55 μm and 1.65 μm wavelengths) for a 1.5 GHz band cellular system is constructed to evaluate the fundamental characteristics of the proposed system. As a result, it is shown that the proposed system triples the radio service coverage of The original MSOL with the same signal transmission performance. This system can be used for expanding the service area of cellular portable radios into indoor areas