I was hoping I could get some advice on what is a good block-design strategy for the following problem.
I have two streams of complex samples coming in. I want a block or sequence of blocks which outputs the cosine of the phase difference between the two input streams.
If we could assert that both input streams are unit length, then one way to do it would be to conjugate one stream, then complex multiply the two together, then take the real part of the output. But if the input streams are NOT normalized, then the product will likely not be unit length either, and this won't work.
We could try and normalize the complex product, but the universe explodes if it has length 0 (divide by 0). Also, this would require a slow sqrt (?)
Is the best approach to just get the phase of the complex product via fast_atan2f, then take the cos of that?
Do any basic math/trig functions (cos, atan2, sqrt, etc) exist at the python block level, or do I have to delve into C to use them? Makefiles are scary :(