Thanks Markus,
What does minor SNR degradation mean, in dB, and on what does this
value depend? (e.g. transmission time, symbol length, etc).
73, Stefan
Am 07.06.2017 17:59, schrieb Markus Vester:
Dear EbNauteers,
I recently stumbled upon a bug in my ebnaut_ifft3a utility, which
is used to convert SpecLab FFT export files to IQ wav files. The first
step of the inverse FFT is to take the complex conjugate of the data
array. Due to the bug, the respective loop was executed only N-1 times,
leaving a sign error in the imaginary part of a single bin next to the
center frequency. When fed with a high-SNR signal close to SpecLab's
center frequency, this can produce strange undulation patterns in the
phase display and a minor SNR degradation for the decoder.
The bug has been fixed in version 3b, available on
http://df6nm.bplaced.net/VLF/fec_tests/ebnaut_ifft3b.zip
Best regards,
Markus (DF6NM)
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