| 主权项 |
1. A method of detecting a digital leakage signal originating from a leak in a coaxial cable portion of an HFC network, the HFC network having a transmission end from which a digital signal is transmitted to the coaxial cable portion, the digital signal being emitted into free space from the leak to produce the digital leakage signal, said method comprising the steps of:
(a) producing a first set of signal samples representing the digital signal, at a sampling rate synchronized to a reference clock signal; (b) transmitting the first set of signal samples to a leakage detector; (c) moving the leakage detector to a detection point in the vicinity of the coaxial cable portion of the HFC network; (d) receiving, at the leakage detector at the detection point, the digital leakage signal from the leak; (e) sampling the digital leakage signal at the leakage detector, at a sampling rate synchronized to the reference clock signal and during a time interval initiated in synchronism with a timestamp associated with the digital signal at the transmission end, to produce a second set of signal samples; and (f) performing a cross-correlation of the first set of signal samples with the second set of signal samples, to produce a cross-correlation function having a correlation peak, whereby the digital leakage signal is detected from the correlation peak. |
