Siia Chen
2016-12-22 07:25:26 UTC
Hello,
In https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spectral_scan
and https://wiki.freebsd.org/dev/ath_hal%284%29/SpectralScan and a few
mails on this list I have seen it stated that the FFT data for each
bin is reported as the sum of the absolute magnitudes of both I and Q
components, i.e, |i|+|q|. However, I have also seen the square of the
returned bin value being directly plugged into the formula for
estimating the bin power in numerous post-processing applications,
which doesn't make sense for me. As power is calculated by i^2+q^2,
which doesn't equal to (|i|+|q|)^2. Can anybody kindly clear this up
for me? Thanks a lot.
Best wishes,
Robert
In https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spectral_scan
and https://wiki.freebsd.org/dev/ath_hal%284%29/SpectralScan and a few
mails on this list I have seen it stated that the FFT data for each
bin is reported as the sum of the absolute magnitudes of both I and Q
components, i.e, |i|+|q|. However, I have also seen the square of the
returned bin value being directly plugged into the formula for
estimating the bin power in numerous post-processing applications,
which doesn't make sense for me. As power is calculated by i^2+q^2,
which doesn't equal to (|i|+|q|)^2. Can anybody kindly clear this up
for me? Thanks a lot.
Best wishes,
Robert