Characterizing ingress noise
AssigneeViavi Solutions Inc.
InventorsBen Maxson, Daniel K. Chappell, Jim Walsh
Life of this patent
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Abstract
Methods and devices for characterization of repetitious noise in cable networks are disclosed. A frequency band of interest is identified, a time trace of a signal parameter within the frequency band is obtained, and an autocorrelation of the time trace is computed to detect repetitious noise. The repetition frequency can serve as an indicator of the noise source type, and thus it can assist in noise segmentation.
Claims19
A device to identify noise in a cable network, the device comprising:
- a spectrum analyzer to:
- obtain a frequency spectrum of a cable signal at a first cable network location, wherein the cable signal includes a digital signal from a digital source and noise from a noise source;
- generate a time trace of a first parameter of the cable signal at a first frequency of the obtained frequency spectrum;
- compute an autocorrelation function of the time trace;
- identify a plurality of peaks in the autocorrelation function;
- determine a time delay between the plurality of peaks based on a summation analysis of the computed autocorrelation function and the identified plurality of peaks;
- and
- identify a first repetition frequency of a component of the noise from the time delay, wherein the first repetition frequency is indicative of a type of the noise source.
A method to identify noise in a cable network, the method comprising:
- obtaining, by a hardware processor, a frequency spectrum of a cable signal at a first cable network location wherein the cable signal includes a digital signal from a digital source and noise from a noise source;
- generating a time trace of a parameter of the cable signal at a first frequency of the obtained frequency spectrum;
- computing an autocorrelation function of the time trace;
- identifying a plurality of peaks in the autocorrelation function;
- determining a time delay between the plurality of peaks based on a summation analysis of the computed autocorrelation function and the identified plurality of peaks;
- and
- identifying a first repetition frequency of a component of the noise from the time delay, wherein the first repetition frequency is indicative of a type of the noise source.
A cable network testing device operable to test for ingress noise in a cable network, the cable network testing device comprising:
- an input terminal to couple the cable network testing device to the cable network;
- a spectrum analyzer to:
- receive a cable signal from the cable network via the input terminal, wherein the cable signal includes a digital signal from a digital source and noise from a noise source;
- generate a time trace of a first parameter of the cable signal at a first frequency of a frequency spectrum of the cable signal;
- compute an autocorrelation function of the time trace;
- identify a plurality of peaks in the autocorrelation function;
- determine a time delay between the plurality of peaks based on a summation analysis of the computed autocorrelation function and the identified plurality of peaks;
- and
- identify a first repetition frequency of a component of the noise from the time delay, wherein the first repetition frequency is indicative of a type of the noise source;
- and
- a display to display at least one of the frequency spectrum and the first repetition frequency.
Dependencies are inferred from the claim text.