[time-nuts] Sinlge ADC multi-band receiver
magnus at rubidium.dyndns.org
Mon Apr 10 00:52:47 EDT 2017
On 04/09/2017 10:29 PM, Attila Kinali wrote:
> On Wed, 5 Apr 2017 10:37:07 +0200
> Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
>> Also, you don't really need to keep the bands fully separate in their
>> mixed-down form, since they do not correlate except for the P(Y), but
>> keeping enough frequency difference, such that doppler shift does not
>> remove correlation margin, they remain uncorrelated. Some of the
>> literature pay much attention to the band not wrapping around the
>> band-edge, but I'm not convinced it is such a big issue.
> If part of the signal wraps because you are at the bandedge,
> then you lose this part of the signal and the part it wraps over.
> This is due to the signal coherently overlapping in frequency space.
> As far as I understood the math, there isn't a way to seperate them
> again (at least there isn't any I am aware of). Thus this signal energy
> is lost for the decoding process.
Your generated signal would have the same wrapping. A single bit sampler
would be feasible to loose in, but for multibit ADCs I'm more skeptic.
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