I have a Doppler sensor with I/Q channels for detecting moving object. I need to also detect the moving direction of the object. Due to the limited power and flash memory of my MCU, I cannot afford FFT() or atan() or sqrt() functions.
In order to determine the moving direction of the object, phase difference between I and Q need to be determined (positive or negative). And the following methods are the ones I'm aware of:
- search posive slope of I and Q signal and determine the phase shift
The first 3 methods, I cannot afford them due to MCU limit. The last one is very sensitive to noise.
Is there other simple ways to determine the phase difference between I/Q is negative or positive ?