[email protected] wrote:
My half-penny's worth is that the transmitted energy per symbol is 3.3
times larger, giving exactly 5.23 dB improvement ;-) That's assuming
that the FFT bandwidth is somewhere near the optimum (0.3 Hz and 0.1
Hz respectively).
Markus,
you are correct, but in an ideal situation. Given that for performance
reasons the FFT works at its best when done
on a sample length which is a power of two, in Argo, when going from
QRSS3 to QRSS10 I multiply the sample length
by four, which causes a reduction of four times of the bin size. This
has the consequence that the noise energy that falls
into a single bin is 6 dB lower, hence the 6 dB gain in SNR.
There are algorithms to perform FFTs on arbitrary sizes, but they are
slower than when working with powers of two.
73 Alberto I2PHD
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