FPGA based 1 channel fiber optic analog signal link using 8B/10B encoding scheme

The paper presents the details of development of the fiber optic link that will be used to interconnect the various analog signals. Speciality of the link is that the analog signal of frequency up to 1 kHz is transmitted through digital technology. In order to resolve the problem of DC balance and clock/data recovery during the fiber optic data transmission, paper gives a simple and practical solution of 8B/10B encoding and decoding techniques. The paper also gives the solution of clock and data recovery (CDR) by using the 4×-oversampling based digital techniques. The design of 8B/10B encoder has been implemented on transmitter and 8B/10B decoder in receiver module. This solution gives a method of checking scheme and logic operation, through VHDL description language. The proposed circuit is simulated in Xilinx 14.2 ISE tool and implemented on Spartan 3E FPGA. The results obtained from the various tools are presented in this paper. For analog signal link, paper gives the interfacing of analog to digital convertor (ADC) with FPGA in transmitter module and digital to analog convertor (DAC) with FPGA in receiver module.