Patent ID: 7584496
Filing Date: 2009-09-01
Classification: H04N

Abstract:
1. An apparatus for pinpointing a CPD source in a CATV network that carries a plurality of TV program signals in a forward path frequency band and return path signals in a return path frequency band, said apparatus comprising: (a) a first input for receiving the plurality of TV program signals from the CATV network; (b) a CPD generator coupled to said first input and configured to generate a plurality of intermodulation products from the plurality of TV program signals, for use as a reference signal; (c) a second input for receiving the return path signals from the CATV network, the return path signals including intermodulation products of the plurality of TV program signals created by the CPD source in the CATV network; (d) a first time delay unit coupled to said CPD generator to receive the reference signal, said first time delay unit being adapted to delay the reference signal and create a delayed reference signal; (e) a correlator coupled to said first time delay unit to receive the delayed reference signal and coupled to said second input to receive the intermodulation products created by the CPD source, said correlator being adapted to perform a cross-correlation of the delayed reference signal with the intermodulation products created by the CPD source and produce a cross-correlation function; and (f) a processor coupled to said correlator to receive the cross-correlation function, said processor being adapted to determine a time delay associated with the CPD source based on the cross-correlation function, whereby the time delay associated with the CPD source is used in pinpointing the CPD source.