Verfahren und Anordnung zur UEbertragung pulsfoermiger Signale mit einem Pilotsignal

摘要

A pulse coded modulated signal is transmitted together with a sinusoidal pilot signal. The frequency of the signal is dependent on the frequency response characteristic of the information signal, and most conveniently is twice the 50% cut-off frequency of the information signal. The receiver then detects the pilot signal and effectively clocks the information accordingly. If this pilot frequency is too high, the 50% cut off frequency may itself be used and by detecting the null points the receiver may also clock the information. Phase shift of the pilot signal in this case may be critical and this feature is examined. A modulator is briefly described in which the pilot frequency is generated, filtered, suitably delayed and mixded with the outgoing pulse coded signal to give the required transmitted signal.