Re: [Discuss-gnuradio] Why 4 ADC's?

[Ian Larsen]

Thank you, that's very helpful.

I assume this also true for the BasicRX daughterboard?  (Doesn't do
downconversion, but does do analog multiplication to get I and Q?)

-Ian

On 7/18/07, Johnathan Corgan <address@hidden> wrote:
> Ian Larsen wrote:
>
> > I have a conceptual question about the USRP.  Why are there 4 A/D
> > converters?  Is it only for flexibility reasons, or can you acheive
> > double the sampling rate by clocking two of them 180 degrees of from
> > each other and interleaving the resulting data?
>
> Neither.
>
> Each daughterboard receiver does complex analog downconversion and
> produces two resulting baseband signals, the in-phase (I) and quadrature
> (Q) outputs.  Each of these is sampled by a separate ADC, and with up to
> two receiver boards, this requires all four ADCs present.
>
> --
> Johnathan Corgan
> Corgan Enterprises LLC
> http://corganenterprises.com