Correlation systems and methods with error compensation
AssigneeAdtran, Inc.
InventorsMichael D. Turner, Leif J. Sandstrom, John Gordon Brooks
Life of this patent
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Abstract
A correlation system, such as a correlation optical time domain reflectometer (OTDR) system, transmits a correlation sequence, such as an M-sequence, and measures the returns of the correlation sequence over time. The system correlates the transmitted sequence with the returns to provide correlation measurement values that respectively correspond to different distances from the point of transmission. A correlation error compensation element adjusts each correlation measurement value in order to cancel the contribution of the correlation error floor from the measurements to provide compensated measurement values that are substantially free of the effects of the correlation error floor.
Claims22
A correlation system, comprising:
- a transmitter configured to transmit a correlation sequence;
- receive circuitry configured to receive returns from the transmitted correlation sequence;
- a plurality of correlators coupled to the receive circuitry and configured to correlate the correlation sequence with the returns to provide a set of correlation measurement values respectively associated with the returns, wherein the set comprises a respective correlation measurement value from each of the correlators, each of the correlation measurement values corresponding to a respective distance from the transmitter and indicative of a condition at the corresponding distance, wherein one of the correlation measurement values associated with one of the returns is corrupted by error from a plurality of the returns;
- and
- a correlation error compensation (CEC) element configured to receive the correlation measurement values and to adjust the one correlation measurement value based on a plurality of the correlation measurement values thereby compensating the one correlation measurement value for the error.
A correlation method, comprising:
- transmitting a correlation sequence from a transmitter;
- receiving returns from the transmitted correlation sequence;
- correlating the correlation sequence with the returns to provide a set of correlation measurement values respectively associated with the returns, each of the correlation measurement values corresponding to a respective distance from the transmitter and indicative of a condition at the corresponding distance, wherein one of the correlation measurement values associated with one of the returns is corrupted by error from a plurality of the returns;
- and
- adjusting the one correlation measurement value based on a plurality of the correlation measurement values thereby compensating the one correlation measurement value for the error.
Dependencies are inferred from the claim text.