Measurement method for phase difference among same-frequency signals based on SOBI (Second Order Blind Identification) and FastICA (fast Independent Component Analysis)

Abstract

The invention relates to a measurement method for phase difference among same-frequency signals based on SOBI (Second Order Blind Identification) and FastICA (fast independent component analysis). The method comprises the following steps: 1. extending a tested signal x(n) into a three-dimensional 3D observation signal matrix X(n); 2. operating the sequenced non-iterative SOBI algorithm for the observation signal matrix X(n) once so as to obtain a separation matrix W1; 3. adopting W1 as an initial value of the separation matrix and operating the FastICA algorithm for the observation signal matrix X(n) once so as to obtain a hybrid matrix A and a source component matrix S(n); 4. synthesizing tested signal content x'(n) according to the hybrid matrix A and the source component matrix S(n); and 5. comparing the tested signal x'(n) with a standard signal so as to obtain a phase difference, thus completing the measurement of the phase difference among the same-frequency signals. The measurement method for the phase difference among the same-frequency signals based on the SOBI and FastICA provided by the invention can lower the requirements of measurement samples and increase the measurement accuracy.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to a method for measuring phase difference of same-frequency signals based on SOBI and FastICA. Background technique [0002] Phase difference measurement of periodic signals with the same frequency is widely used in signal analysis, circuit parameter testing, electrical technology, industrial automation, intelligent control, communication and electronic technology, etc. Determination of power factor angle, etc. [0003] In engineering measurement, due to the complexity of the environment in which the measurement equipment is located, the measured signal is often superimposed with one or another noise, such as: zero drift, ringing, glitches, temperature drift, harmonic interference, white noise interference, etc. . These noises usually cause the shape of the measured signal to be distorted, or even submerged in the noise, causing serious difficulties to the measurement. ...

AI Technical Summary

Problems solved by technology

[0006] To sum up, the prior art sinusoidal signal phase difference measurement method has the following defects: the measurement sample is required to have a high signal-to-noise ratio, the applicability is poor, and it is difficult to meet the measurement requirements in complex environments; the measurement accuracy is too dependent on Measure the length of the sample, and it is difficult to eliminate harmonic interference, and the measurement speed is slow

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