| 摘要 |
An optical repeater receives a signal A comprising a main, CMI-coded signal with superimposed sub-information signal bits which violate every nth bit of the main signal. The received signal A is processed by an opto-electronic converter 1, a circuit 2 extracting a timing signal B, a regenerating circuit 3 and a CMI decoding circuit 4 which extracts the main signal and a violation signal C representative of sub-information. A violation signal generating circuit 5 superimposes new sub-information signals DO min etc. to form a violation signal J which is imposed on the main signal by a coding circuit 6, whose output is applied to an electronic-to-optical converter 7. In the generating circuit 5 an error detecting circuit 52 produces an error pulse E for each detected error in the violation signal C. An error position varying circuit 53 varies the phase of the error pulse E in order to prevent a transmission error being erased by the superimposition of the local sub-information H. The phase-adjusted error pulses I are added in a circuit 54 to the local sub-information signal H to form the violation signal J. |
