Method and apparatus for characterizing a signal path carrying an operational signal

A method of testing a signal path having an anomaly, comprising:

• generating a first reference spread-spectrum signal and a second reference spread-spectrum signal;
• coupling the first spread-spectrum signal into the signal path at a first location while the signal path is carrying an operational signal;
• coupling the second spread-spectrum signal into the signal path at a second location different than the first location while the signal path is carrying the operational signal;
• receiving at a third location a first reflected spread-spectrum signal from the signal path generated by the anomaly in response to the first and second spread-spectrum signals;
• receiving at a fourth location a second reflected spread-spectrum signal from the signal path generated by the anomaly in response to the first and second spread-spectrum signals;
• correlating the first reflected spread-spectrum signal with the first reference spread-spectrum signal to produce a first correlation result;
• correlating the second reflected spread-spectrum signal with the second reference spread-spectrum signal to produce a second correlation result;
• and
• combining the first correlation result and the second correlation result to determine a location of the anomaly having increased accuracy relative to a location determined using either the first correlation result or the second correlation result alone.

A system for characterizing a signal path carrying an operational signal comprising:

• a signal generator configured to generate a reference spread-spectrum signal wherein the reference spread-spectrum signal has a spectrum shaped to substantially inversely mirror a spectrum of the operational signal;
• an interface coupled to the signal generator and configured to inject the reference spread-spectrum signal into the signal path and configured to extract a reflected spread-spectrum signal from the signal path generated in response to the reference spread-spectrum signal;
• and
• a correlator coupled to the signal generator and coupled to the interface and configured to correlate the reflected spread-spectrum signal with the reference spread-spectrum signal to produce a correlation result corresponding to a characteristic of the signal path.

An electronic system for detecting an anomaly in a signal path carrying an operational signal comprising:

• a plurality of signal generators configured to generate a plurality of reference spread-spectrum signals wherein the plurality of reference spread-spectrum signals each have a spectrum shaped to substantially inversely mirror a spectrum of the operational signal;
• at least one injector coupled to the plurality of signal generators and configured to inject the plurality of spread-spectrum signals into the signal path;
• at least one extractor coupled to the signal path and configured to extract a plurality of reflected spread-spectrum signals from the signal path generated by the anomaly in response to the plurality of reference spread-spectrum signals;
• at least one correlator coupled to the plurality of signal generators and coupled to the at least one extractor and configured to correlate the plurality of reflected spread-spectrum signals with the plurality of reference spread-spectrum signal to produce a plurality of correlation results;
• and
• a processor coupled to the at least one correlator and configured to determine a location of the anomaly from the plurality of correlation results.