New type of optical fiber SSB analog data communication system using edge-emitting LEDs coupled to single mode optical fibers

摘要

This paper describes a new type of factory communication system using optical fibers. This new type of optical fiber SSB data communication system consists of a pair of optical transmitters, each transmitter constructed using an edge-emitting LED (ELED), a pair of optical receivers and a pair of single-mode-optical fibers, each having a length of 12 km. A pair of 12 channels are assigned to SSB data with frequencies of 12 kHz through 60 kHz in the lower frequency band on the up-going link, and of 72 kHz through 120 kHz in the higher frequency band on the down-going link, respectively. The transmitter and receiver are housed in a transmitter-receiver unit. When the transmission was experimentally carried out, the spurious noise was below -50 dB on each channel, and SNR was more than 60 dB. This system can be used to send status and voice data for the electrical and mechanical machines in place of power line communications.