Patent attributes
A method and apparatus is disclosed for enabling synchronous capture of forward and return signals at a remote PHY device for detecting CPD. The remote PHY device provides the forward signal to and receives the return signal from a coaxial cable plant. The return signal contains an actual CPD signal generated by an interaction between the forward signal and a CPD source in the cable plant. The forward signal propagates from the remote PHY device to the CPD source and the actual CPD signal propagates from the CPD source to the remote PHY device all within a round-trip interval. The method comprises: capturing the forward signal from an output associated with the remote PHY device; generating from the forward signal a simulated CPD signal having frequencies in a return channel; band-limiting the simulated CPD signal to the return channel to produce a reference CPD signal; supplying the reference CPD signal to the remote PHY device; in the remote PHY device, receiving the reference CPD signal in the return channel; and (f) in the remote PHY device, capturing the return signal from the return channel over a capture duration of at least the round-trip interval. The reference CPD signal is used to detect the actual CPD signal from the return signal.
