Optically Powered Remote Units for Radio-Over-Fiber Systems

Optically powered radio-over-fiber remote units have been designed and constructed for distributed antenna system applications using separate fibers for power and signal transmission. The feasibility of this approach has been investigated through a series of transmission measurements, based on the IEEE 802.11g wireless local area networking standard at a frequency of 2.5 GHz using 64-QAM OFDM modulation at 54 Mb/s. These measurements show that high-quality multilevel signal transmission is possible with modest levels of optical power at the central unit. For example, an EVM of around 3% has been achieved for an RF output power of 0 dBm using a central unit optical power of 250 mW over a link length of 300 m.