On Tue, Jul 21, 2009 at 11:48, Jason Uher<jasonu...@gmail.com> wrote:
> Don't all of the multi-antenna files require a specific FPGA build > (ie, unique to the USRP1) to get two real signals from a single > daughterboard? Is there such an FPGA build for the USRP2? (I ask > because the multi-antenna scripts don't seem to represent that) The current USRP2 FPGA build treats the Basic/LFRX as I and Q baseband cards, with a single DDC for frequency conversion and sample rate conversion, resulting in a single IQ stream over the GbE. It is possible to write an FPGA image with 2 DDCs that have TX_A and TX_B connectors routed individually as I channels (with Q set to 0.) However, the current host interface does not provide a way to independently set two different DDC parameters (frequency and decimation) or to receive two sample streams. Long term, this will get fixed when we have the VRT interface in release 3.3. Short term, there will be an alternate FPGA build that does the above, but the two DDCs will share conversion frequency and decimation, and will result in an interleaved I1Q1I2Q2 type stream. This would at least allow coherently sampling two baseband inputs. Johnathan _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
