You need more than 1 bit change to get voice data. I find you need to be about
15 dB above the niose floor to decode AM. I don't know the real number but it
does reduce the system dynamic range.
[EMAIL PROTECTED] wrote: Sis108 <[EMAIL PROTECTED]> wrote :
> It is correct that a 14-bit AD-Converter exhibits an effective signal
> to noise ratio of only 75dB.
The maximum S/N ratio for 14-bit converter is 86 dB, therefore 75 dB sounds
realistic.
> However, this value comprises for the
> whole bandwidth of 32MHz. By filtering appropriately and therefore
> reducing the bandwidth B, a process gain of P = 10*Log10(32MHz/B) can
> be achieved. With B=2400Hz, the process gain results in ca. 41dB,
> therefore the dynamic range is increased to 75 + 41 = 116dB.
This is certainly true ON AVERAGE, but may fail in individual cases,
depending on the nature of the quantization noise.
73,
Sinisa YT1NT, VE3EA
