METHOD AND APPARATUS FOR RECEIVING A DATA SIGNAL MODULATED BY MEANS OF A DOUBLE SIDEBAND-QUADRATURE CARRIER MODULATION TECHNIQUE

摘要

ABSTRACTMETHOD AND APPARATUS FOR RECEIVING A DATA SIGNALMODULATED BY MEANS OF A DOUBLE SIDEBAND-QUADRATURECARRIER MODULATION TECHNIQUEA method and apparatus for receiving a data signalmodulated by means of a double sideband-quadraturecarrier modulation technique in which the receivedsignal is sampled at a rate higher than the sign-aling rate 1/T, passed through a compensatingfilter, and applied to a processing system whichprovides the detected data. The compensatingfilter is such that the amplitudes of the com-ponents at f1=fc-1/2T and f2-fc+1/2T, where fc isthe carrier, are equal. An initializer enables afilter coefficient to be determined during theturn-on time of the receiver. An adjusting deviceallows this coefficient to be continually adjust-ed. The invention can be used in data transmissionsystems whose channel has an asymmetric amplitude-frequency response curve.