All-digital Outphasing Modulator for Radio-over-Fiber System

An all-digital outphasing modulator for radio-over-fiber (RoF) system is presented. In this system, a pair of rectangular outphasing signals are generated in an all-digital outphasing modulator as 1-bit streaming data and transmitted to an optical fiber. In measurement results, signal to noise ratio (SNR) of 30 dB is achieved for 100 MHz bandwidth OFDM signal after fiber transmission. Additionally, the cost efficiency, defined as signal bandwidth versus device speed required for optical transceiver, in proposed system is higher than conventional RoF systems with 1-bit modulation.