| 摘要 |
A pseudo-random noise binary signal is transmitted together with the information signal from a LWL connection unit. A small part of the optical signal is branched off at the passive interface and transmitted back to the connection unit, where it is supplied together with the optical signal received from the other end to the optoelectric transducer. The electric reception signal is correlated with the original, in the meantime delayed pseudo-random noise binary signal, and the thus obtained correlation signal amplitude indicates the occurrence or non-occurrence of the pseudo-random noise binary signal reflected by the passive interface (PNT1), taking into account the signal propagation time. |
