Laser measurement system with digital delay compensation
AssigneeAgilent Technologies, Inc.
InventorsLee Charles Kalem, David Todd Dieken
Life of this patent
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Abstract
A method and system for determining and compensating for phase and time errors in an optical receiver. The method and system includes use of a measurement and reference signal; deriving phase and time errors; and providing compensation values to the optical receiver. The operating frequency and/or other operating parameters associated with phase and time errors are determined and recorded to allow for proper compensation to the optical receiver.
Claims15
A method of computing phase difference between a measured signal and a reference signal, the method comprising:
- measuring a first cycle of the measured signal to arrive at a first denominator;
- measuring a first cycle of the reference signal to arrive at a second denominator;
- calculating a time after the first cycle of the measured signal and a subsequent pulse of a reference clock signal to arrive at a first numerator;
- calculating a time after the first cycle of the reference signal and the subsequent pulse of the reference clock signal to arrive at a second numerator;
- dividing the first numerator by the first denominator to arrive at a first quotient;
- dividing the second numerator by the second denominator to arrive at a second quotient;
- and
- deriving a difference between the first and second quotients to arrive at a first position value, wherein the position value translates to a first phase difference.
A method of computing time difference between a measured signal and a reference signal, the method comprising:
- measuring a first cycle of the measured signal to arrive at a first denominator;
- calculating a time after the first cycle of the measured signal and a subsequent pulse of a reference clock signal to arrive at a first numerator;
- calculating a time after the first cycle of the reference signal and the subsequent pulse of the reference clock signal to arrive at a second numerator;
- and
- deriving a difference between the first and second numerators to arrive at a first time difference value.
A method of computing phase difference between a measured signal and a reference signal, the method comprising:
- receiving the measured signal from a first receiver wherein the measured signal provides a pulse on each cycle;
- generating a reference clock signal and a measurement clock signal;
- receiving the reference signal from a second receiver wherein the reference signal provides a pulse on each cycle;
- calculating a measurement denominator value based on a first pulse and a succeeding second pulse of the measured signal wherein the value is calculated against the measurement clock signal;
- calculating a measurement numerator value based on the second pulse of the measured signal and a next succeeding pulse of the reference clock signal;
- deriving a measurement quotient value by dividing the measurement numerator value by the measurement denominator value;
- calculating a reference denominator value based on a first pulse and a succeeding second pulse of the reference signal wherein the value is calculated against the measurement clock signal;
- calculating a reference numerator value based on the second pulse of the reference signal and a next succeeding pulse of the reference clock signal;
- deriving a reference quotient value by dividing the reference numerator value by the reference denominator value;
- and
- calculating a difference between the measurement quotient value and the reference quotient value to arrive at a position value, wherein the position value relates a phase difference.
A method of computing time difference between a measured signal and a reference signal, the method comprising:
- receiving the measured signal from a first receiver wherein the measured signal provides a pulse on each cycle;
- generating a reference clock signal and a measurement clock signal;
- receiving the reference signal from a second receiver wherein the reference signal provides a pulse on each cycle;
- calculating a measurement denominator value based on a first pulse and a succeeding second pulse of the measured signal wherein the value is calculated against the measurement clock signal;
- calculating a measurement numerator value based on the second pulse of the measured signal and a next succeeding pulse of the reference clock signal;
- deriving a measurement quotient value by dividing the measurement numerator value by the measurement denominator value;
- calculating a reference numerator value based on the second pulse of the reference signal and a next succeeding pulse of the reference clock signal;
- calculating a difference between the measurement numerator value and the reference numerator value to arrive at a time difference value.
Dependencies are inferred from the claim text.