Millimeter -wave Radio on Fiber System for Digital Broadcasting Signals
Tsuyoshi NAKATOGAWA, Mikio MAEDA and Kimiyuki OYAMADA↓summary
ABSTRACTRoF（Radio on Fiber）is an attractive delivery method for areas or homes where it is difficult to install optical fiber cables. We have proposed a transmission method that provides multi-channel digital broadcasting services to subscribers on FTTH（Fiber To The Home）and millimeter-wave RoF networks using self-heterodyne technology. This paper describes a method for single side band（SSB）modulation with a reduced carrier, which increases the optical modulation index （OMI）by tuning the applied bias voltages of an external optical modulator. This method can increase the OMI and improve the reception CNR（Carrier-to-Noise Ratio）of millimeter-waves by 14 dB. In addition, we propose a novel millimeter-wave receiver for subscribers using selfheterodyne detection. The receiver separates the carrier and the side band and eliminates thermal noise close to the carrier. It can improve sensitivity by 10 dB compared with a conventional self -heterodyne receiver. A wireless transmission experiment proved the practicality of the receiver and the RoF system.