Method and system for processing a signal to extract a useful signal from a disturbed signal

A method for processing a disturbed signal P1 transmitting data on a communication bus of an electronic circuit, the method being implemented by a processing device, the method enabling a useful signal to be extracted from the disturbed signal P1, the disturbed signal P1 being measured by a first sensor of the processing device, the disturbed signal P1 being formed as a sum of a sinusoidal component S1 and an additional component X1, the useful signal corresponding to the additional component X1, values of the useful signal being representative of the data transmitted on the communication bus, the method comprising:

• determining values of the disturbed signal P1 at three successive times t1, t2 and t3;
• determining values, at the three successive times t1, t2 and t3, of a signal P2 comprising a sinusoidal component S2 of a same amplitude as the sinusoidal component S1 and in phase quadrature with respect to the sinusoidal component S1;
• and
• calculating a value of the useful signal at time t3 as a function of the values of the disturbed signal P1 and the values of the signal P2 at the three successive times t1, t2 and t3.

A processing device to process a disturbed signal P1, transmitting data on a communication bus of an electronic circuit, to extract a useful signal from the disturbed signal P1, the device comprising:

• a first sensor to measure the disturbed signal P1, the disturbed signal P1 being formed as a sum of a sinusoidal component S1 and an additional component X1, the useful signal corresponding to the additional component X1, values of the useful signal are representative of the data transmitted on communication bus;
• a processor configured to:
• determine, based on measurements performed by the first sensor, values of the disturbed signal P1 at three successive times t1, t2 and t3;
• determine values, at the three successive times t1, t2 and t3, of a signal P2 comprising a sinusoidal component S2 of a same amplitude as the sinusoidal component S1 and in phase quadrature with respect to the sinusoidal component S1;
• and
• calculate a value of the useful signal at time t3 as a function of the values of the disturbed signal P1 and the values of the signal P2 at the three successive times t1, t2 and t3.