METHOD OF MEASURING PHASE SHIFT Russian patent published in 2014 - IPC G01R25/00 

FIELD: radio engineering, communication.

SUBSTANCE: method includes generating a third and a fourth signal by delaying a first and a second signal by one interval, all products of even and odd signals, from which a first and a second value are generated, estimating the measured phase shift between the first and second signals as the arctangent of the ratio of time-averaged values of the first and second values; further generating fifth, seventh and ninth signals by delaying the first signals by two, three and four intervals, respectively, sixth, eighth and tenth signals by delaying the second signal by two, three and four intervals, respectively; generating a third value as the difference between the product of the second signal and the ninth signal and the product of the first signal and the tenth signal, a fourth value as the difference between the product of the fourth signal and the seventh signal and the product of the third signal and the eighth signal; generating a fifth value as the difference between the product of the fourth signal and the seventh signal and the product of the fifth signal and the sixth signal, a sixth value as the difference between the product of the third signal and the eighth signal and the product of the fifth signal and the sixth signal, a seventh value as the sum of the product of the fourth signal and the seventh signal and the product of the third signal and the eighth signal, an eighth value as the sum of the product of the third signal and the fourth signal and the product of the seventh signal and the eighth signal; wherein measurement is carried out in two steps, at the first step of which a first value is generated as the product of the fourth value and the sum of the fifth and sixth values and the square root of the difference between the square of two times the fourth value and the square of the third value, and a second value is generated as the product of the square of the sum of the fifth and sixth values and the sum of two times the fourth and third values; at the second step of which the first value is generated as the product of the magnitude of the fourth value and the difference between the product of the third and seventh values and two times the fourth and eighth values and the product of the square root of the difference between the square of two times the fourth value and the square of the third value, and the second value is generated as the square of the difference between the product of the third and seventh values and the product of two times the fourth and eighth values, and an estimate with the minimum mean-square deviation is selected from the phase shift estimates obtained at the first and second steps.

EFFECT: reduced error of measuring phase shift of quasi-harmonic signals with slow-varying amplitude and frequency in the presence of additive and multiplicative interference.

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