Code conversion circuit for optical duobinary transmission and optical transmitter and receiver using same

摘要

A code conversion circuit provided with a bit distributing unit for dividing a high speed input signal into N ways of low speed signals, N number of code converters for performing code conversion on the N ways of low speed signals, and a bit combining unit for receiving as input code-converted low speed signals output from the N number of code converters and logically adding and combining these to produce a code-converted high speed output signal, whereby it becomes possible to ease the harsh restriction on the delay time with respect to one time slot imposed on a delay element in a pre-coder used for optical duobinary transmission.