So I'm doing some digital signal processing. I have a a current and a voltage signal that I am multiplying together and then filtering through a lowpass filter to get a signal that equals A*B*cos(phi)/2. At this point I want to find phi, so I need the inverse cosine function.
Unfortunatly I'm having troubles trying to write a cordic algorithm because I'm confused starting with a polar coordinate system. Everything I've read only shows rectanglular coordinates. This is my first time doing any sort of dsp so I would appreciate any help or advice.
Cordic can be used in two modes:
Rotational Mode
Vectoring Mode
To compute, arcsine, use CORDIC algorithm in Vectoring mode, with the following initializations:
x0 = 1/An (Process Gain)
y0 = input (for which you need compute arcsine)
z0 = 0
To get arccosine, value use the above algo and adjust accordingly based on the quadrant.