| 摘要 |
PURPOSE:To send pilot information from an FED side to an opposite station as it is through an ADPCM (adaptive difference pulse code modulation) line by using an idle bit of a Nonsyncwords of an ADPCM primary group signal frame. CONSTITUTION:A pilot signal at an FDM(frequency division multiplex) side is extracted by a pilot extraction section 11 of a digital signal processing section 3 and subject to format conversion of 2.048Mbit/s ADPCM frame at a format conversion unit 14 of an ADPCM conversion section 5. For example, Nonsynchwords of a time slot 0 and idle 2-bit of a frame 1 are used to contain information of a group 1 pilot and a group 2 pilot. Moreover, idle 2-bit of a frame 3 is used to contain information of a group 3 pilot and a group 4 pilot, information of a group 5 pilot is contained in a 1-bit in an idle bit of a frame 5 and a pilot signal from the FDM side is sent to the ADPCM side. Thus, an idle bit of a Nonsyncwords of an ADPCM primary group signal frame is used to monitor the pilot. |
