So I think THIS is the curve you should be trying to use to convert BER to
SNR. The question I have it, what are the units of the 22-bit value read from
the chip? How do you convert this to the fraction of the bits in error?
Divide by the gross bitrate (bandwidth in MHz times two)?
The meaning of the 22-bit error counter value is configurable, but it's
always a count of some type of error over a fixed window. Per the
datasheet, the demod is currently configured by the driver to return a
count of reed-solomon block errors with a window size of 65280 blocks
(which is the maximum)
If the datasheet is accurate, I don't see how the value would ever be
greater than 65280 given its configuration (since you can't have more
than 100% of the blocks in the window bad), so we're only looking at 16
bits of significance out of the 22. I assume the extra bits are there
because you can request error rate for bytes or bits as well, which
would give correspondingly greater maximum counts.
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