Addressed multifrequency data transmission using an optical fiber

This paper describes the optical fiber transmission of addressed multifrequency signals on 2 data channels. Each of a pair of data channels and an address signal channel consists of 4 bits which correspond to multifrequencies at 210 kHz, 520 kHz, 715 kHz, and 1.02 MHz. Data on the data channels modulates the PM subcarriers at 5.0 MHz and 8.5 MHz. Address signals on the address channel modulate the FM subcarrier at 2.3 MHz. These FM subcarriers are grouped by mixer and fed to the VCO used as an SWFM modulator operating at 20 MHz before being sent to the electrical-to-optical (E/O) converter. The electrical SWFM signal is converted into the optical SWFM signal by the E/O converter, the optical SWFM signal is fed from the sender to the receiver through the GI optical fiber, and the optical SWFM signal is converted into the electrical SWFM signal at the receiver. The GI optical fiber is used to send digitized temperature data at low speed over a distance of 1 km. Data was satisfactorily transferred between the sender and the receiver.