Non-orthogonality adjustment based on a duty cycle

A system including an orthogonality adjustment processor that comprises:

• a first input to receive a first signal having a sinusoidal waveform;
• a second input to receive a second signal having a sinusoidal waveform;
• a coefficient estimation circuit configured to:
• generate a composite signal responsive to the first and second signals, and
• determine an orthogonality adjustment coefficient based on a duty cycle of the composite signal;
• a compensation circuit configured to apply the orthogonality adjustment coefficient to generate an adjusted second signal;
• a first output to provide the first signal;
• and
• a second output to provide the adjusted second signal.

A method implemented in electronic circuitry, the method comprising:

• receiving a time-varying input signal;
• generating a sign signal indicating a sign of the input signal;
• calculating a duty cycle of the sign signal;
• estimating a signal offset value by comparing the calculated duty cycle to a threshold value;
• and
• subtracting the signal offset value from the input signal to generate an output signal having zero offset.