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Re: [Discuss-gnuradio] Low-cost hardware options
From: |
Peter F Bradshaw |
Subject: |
Re: [Discuss-gnuradio] Low-cost hardware options |
Date: |
Sun, 16 Jan 2011 13:38:38 +0800 (WST) |
On Sat, 15 Jan 2011, Brian Padalino wrote:
>
> It's all about power, right? So you may sacrifice sample rate for
> accuracy, but you can gain those bits back in the digital domain via
> filtering. Only if you really want to see more than the 72dB of
> dynamic range the ADC supplies do you somewhat get screwed, I think.
> I've heard of people recovering very narrowband signals with
> narrowband blockers where the desired signal is below the dynamic
> range at their fastest sample rate, but through digital filtering were
> able to bring the signal out of that noise floor. I haven't done it
> myself.
Of course. This is the principle that underlies Sigma-Delta ADCs.
In my view wider bandwidth and lower resolution is the way to go because
it gives the user a usefull trade off. That is, the user can opt for a
full bandwidth of F_s / 2 at the ADC's resolution or a narrower
bandwidth with processing gain. The processing gain is F_s / (2 * B)
where B is the bandwidth of the discrete filter.
Having said that it is usefull to maximize 2 * F_s / b with respect to
purchase cost where b is the number of ADC bits.
Cheers
--
Peter F Bradshaw: http://www.exadios.com (public keys avaliable there).
Personal site: http://personal.exadios.com
"I love truth, and the way the government still uses it occasionally to
keep us guessing." - Sam Kekovich.
[Discuss-gnuradio] Re: Low-cost hardware options, Patrick Strasser, 2011/01/15