Building a Software Defined Radio

[pacman101]

Hey all,

I am trying to build a software defined radio for educational purposes.

I need some help in understanding how to pick a A/D and D/A board tha
would interface correctly to my SP605 board.

Are there any design considerations that I have to make (aside fro
sampling rate, number of effective bits, snr) to make sure that i
interfaces correctly to my board?





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[rickman]

On Nov 10, 9:37 am, "pacman101" <acosta.janp@n_o_s_p_a_m.gmail.com>
wrote:

Hey all,

I am trying to build a software defined radio for educational purposes.

I need some help in understanding how to pick a A/D and D/A board that
would interface correctly to my SP605 board.

Are there any design considerations that I have to make (aside from
sampling rate, number of effective bits, snr) to make sure that it
interfaces correctly to my board?  

Clocking is very important in an SDR. Phase noise adds noise to your
signal and sets a floor for the sensitivity of the receiver. Select a
board that uses a clock source with low phase noise.

The other parameters you mention, SNR, ENOB, Fs, are all factors that
only matter once you have decided on what signals the radio will
receive. ENOB will affect SNR, but is not equivalent to SNR. Noise
can be averaged out in the filtering so that SNR can improve as the
signal is processed. Fs depends on the band width of the received
signal and how you plan to handle the analog to digital conversion.
For example you can sample so the signals are below the Nyquist
frequency or you can under-sample to perform a down conversion.

Rick