SIGNAL TRANSMISSION SYSTEM

摘要

PURPOSE:To prevent reduction of the signal effective transmission speed by decoding or demodulating only a series signal having the largest amplitude among mixed signals. CONSTITUTION:An optical signal S11 passes through an optical branching device 12 and an optical confluence device 13 and its level is largely decreased. An optical signal via a terminal section 14 is sent from an optical transmitter 17 as an optical signal S12 and confluents together the optical signal S11 at the output of the optical confluence device 13. A mixed signal S13 is converted into an electric signal by a photoelectric converter 19 of an optical receiver 18 and a signal discriminator 20 discriminates '1' or '0' in reference with a threshold level set in advance and outputs an output signal S14 based on the result of criterion. In this case, a level controller 21 always set the threshold level for the signal discriminator 20 between the amplitude level of the series signal having the maximum level and the amplitude of the series signal having the 2nd highest level. Thus, the reduction of the effective transmission speed of the signal is solved.