Method and apparatus for transmission line analysis

A method for performing sequence time domain reflectometry comprising:

• transmitting a sequence signal through a channel;
• receiving a reflected sequence signal;
• and
• processing the reflected sequence signal to determine the location of at least one impedance mismatch on the channel.

A method for processing a reflection signal resulting from transmission of a sequence of bits over a channel to determine the location of one or more line anomalies comprising:

• providing the sequence of bits transmitted over the channel to a prediction module;
• processing the sequence of bits in the prediction module based on coefficient values of the prediction module to generate a prediction module output;
• comparing the prediction module output to a reflection signal;
• and
• modifying the coefficient values, based on the comparing, to cause the prediction module output to generally resemble the reflection signal.

A method for processing reflection to determine the location of line anomalies in a communication channel comprising:

• correlating the reflection with a sequence signal to create a correlated signal, the sequence signal comprising a sequence signal transmitted to generated the reflection;
• locating a signal component in the correlated signal indicative of an impedance mismatch;
• calculating a time period between the beginning of the reflection and the signal component;
• and
• multiplying the time period by one-half the rate of propagation of the reflection through the communication channel to determine the distance between one end of the communication channel and the impedance mismatch.

A method for generating a signal for performing a time domain reflectometry analysis comprising:

• providing a sequence identifier to a sequence generator;
• inputting a generation signal into the sequence generator, the generation signal based on the sequence identifier;
• and
• processing the generation signal to generate a sequence signal, the sequence signal to be used for time domain reflectometry.

A system for performing sequence time domain reflectometry to determine the location of impedance mismatches on a channel being configured to communicate data using a digital subscriber line standard, the system comprising:

• a sequence generator configured to generate a sequence signal;
• a transmitter configured to transmit the sequence signal on a channel causing the sequence signal to propagate through the channel, the channel being analyzed to determine the location of impedance mismatches that may affect data transmission;
• a receiver configured to receive one or more reflections that result from the sequence signal encountering impedance mismatches as it propagates through the channel;
• a correlator configured to correlate the one or more reflections with the sequence signal to generate an output having one or more peaks;
• a processor configured to:
• time the period between a beginning of the sequence signal transmission by the transmitter and at least one of the one or more peaks;
• and
• calculate a value corresponding to a channel length between the system and an impedance mismatch.

A system for performing time domain reflectometry on a communication channel to provide information regarding a location of a line anomaly comprising:

• sequence generator configured to generate a sequence signal;
• a transmitter in communication with the sequence generator and configured to transmit the sequence signal onto the channel;
• a receiver configured to receive signals from the channel and provide the signals to a reflection processor;
• and
• a reflection processor configured to process the reflection to determine a location of a line anomaly.

A system for processing a reflection signal received in response to transmission of a sequence signal over a channel comprising:

• a correlator configured to correlate the reflection signal with the sequence signal to generate a correlated signal;
• a peak detector configured receive the correlated signal and detect a start of the correlation signal and a subsequent peak;
• and
• a timer configured to determine a difference in time between a start of the correlation signal and the subsequent peak, wherein the difference in time can be related to a distance between an end of the channel and a line anomaly.

A system for determining the location of one or more impedance mismatches that affect communication, the system comprising:

• a sequence generator configured to generate a sequence signal for transmission on a channel;
• a transmitter configured to receive the sequence signal and transmit the sequence signal onto the channel;
• a receiver configured to receive a reflection signal from the channel and provide the reflection signal to an impedance mismatch location module;
• an impedance mismatch location module comprising:
• an adaptive filter having two or more coefficient values associated with the adaptive filter, the coefficient values at least partially determining an output of the adaptive filter;
• a comparator configured to compare the output of the adaptive filter with the reflection signal;
• and
• a feedback loop between the comparator and the adaptive filter, whereby feed back received by the adaptive filter via the feedback loop may modify the two or more coefficient values to cause the output of the adaptive filter to generally resemble the reflection signal;
• a coefficient analysis system configured to analyze the two or more coefficients to determine the location of one or more impedance mismatches.

An apparatus for processing a reflection signal to determine a location of a line anomaly comprising:

• means for receiving a reflection signal from a line;
• means for correlating the reflection signal to create a correlated reflection signal;
• and
• means for analyzing the correlated reflection signal to determine the location of one or more line anomalies associated with the line.

A computer program product comprising a computer useable medium having computer program logic recorded thereon for performing time domain reflectometry analysis comprising:

• computer program code logic configured to receive one or more reflections of a sequence signal that are caused by the sequence signal encountering impedance mismatches as it propagates through a channel;
• computer program code logic configured to correlate the one or more reflections with the sequence signal;
• computer program code logic configured to process the correlation to determine a time difference value between transmission of the sequence signal and receipt of one or more reflections;
• and
• computer program code logic configured to process the time difference value with regard to the rate of propagation of the sequence signal and the reflection through the channel to determine information regarding a location of the impedance mismatch.