A method and arrangement for the regeneration of the side band used for transmitting a traeger frequency digital signal

摘要

The additional transmission of digital signals via transmission paths set up for the transmission of low-frequency and carrier-frequency analog signals is possible provided that the digital signals are shifted to a higher frequency range by modulation with a carrier which has a suitable frequency and phase. One of the sidebands produced during the modulation is adequate for transmission, although this cannot be directly regenerated. The transmitted sideband is therefore first equalised, amplified and then fed to a modulation device (M) and also to an arrangement (TA) for clock and carrier derivation in which both the carrier (C) required for modulation and the clock (L) required for time regeneration are generated. The modulation produces a digital signal which is regenerated in a conventional regenerator (R) for digital signals which contains an amplitude regenerator (AR1) and a time regenerator (ZR). The described method and the arrangement are particularly suitable for use in PCM systems which also use an existing cable installed for carrier-frequency telephony. IMAGE