Re: [Discuss-gnuradio] Maximum number of DDCs?

[Sylvain Munaut]

Sascha Krissler wrote:
> Greetings,
> 
> from a spectrum of 25Mhz (GSM-900) i would like to sample as
> many 200khz bands as possible. Since the data rate of the usb
> bus is only 8Mhz, i cannot sample all of this 25mhz wide band.
> Still 8Mhz would be enough to transfer 40 distinct 200khz wide
> bands, which are spread over the 25Mhz band. As far as i understand,
> i would have to use 1 daughterboard, 1 ADC and 40 DDCs for this
> to work. Is it possible to build an FPGA image that does that?
> If not, is it possible on the USRP2?

You can just bring the whole 8MHz in a single block then split it on the
PC side. It'll be horribly CPU expensive but if you code a special CUDA
block that would work.

With two daughter board you could bring 4MHz for each and monitor both
up and downlink frequency in s synchronized fashion for 20 ARFCNs.


    Sylvain