Re: [SDRSharp] SDR-5+ HF receiver - All Mode Software Radio


Alberto I2PHD
 

On 9/7/2013 10:18 AM, jdow wrote:


Errr... not really...� the so called "processing gain" is given by this formula :

�� SNR = (6.02N + 1.76) + 10*log10(Fs/Fd) dB

Plugging into it the numbers, a downsampling of 40:1 gives a dB increment of

���� 10*log10(80:2) = ~16 dB

Considering that a bit is equivalent to 6.02 dB, the increment in bits is then

��� 16/6.02 = ~2.66 bits

So the 12-bit resolution will become about 14.66 bits.� Not bad, but nothing
to write home about. But, then, an additional processing gain is obtained in the
SDR program, which will further downsample those 2 MHz, down to, e.g., 24 kHz
where the demodulation is done. Here is where you gain resolution...

73� Alberto� I2PHD

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