[Discuss-gnuradio] White Noise detection and elimination

[Robert James]

I'm working on a series of blocks to measure the level of white noise
and attentuate it.  (Yes, I know there are better ways of doing this,
like a Wiener filter - my goal here is to experiment and learn.)

Model: Assume white noise is present in equal power at all frequencies.

Plan:
Signal --> FFT --> [Find min power val over entire freq vector] -->
[Subtract that min val from all freq] --> IFFT --> Output

Two questions:

1. Will this work?

2. What format does the FFT output vector use? I imagine to find the
min power at any freq I need to write my own block - hopefully I can
do this in Python.  Code to do that in Python is trivial, but I can't
find the FFT output vector format documented.  Likewise for "Subtract"
- I mean this as a mathematical subtraction, *not* attenuation
(multiply), which would attentuate the signal just as much.  So if the
FFT output vector is in a logarithmic format, I need to first turn it
into a linear format before subtracting.