On Thu, Sep 07, 2006 at 04:42:37PM -0700, R and D wrote: > Has anyone done any work on getting sample alignment between multiple USRPs? > > We have multiple USRPs clock-synchronized, but we haven't found a way > to set things up so that the different sample streams hit the D/A > converters at the same clock. > > Any suggestions appreciated. :-)
Welcome mystery person ;) Martin Dvh has gotten multiple USRPs synchronized for receive. That FPGA code and host code is in the subversion. Searching the archives will provide serious clues on how to use it. For transmit, the problem could be a bit more difficult, depending on whether you can deal with a constant phase difference between the transmitting USRPs or not (MIMO vs beam forming). If you need the phases to be identical between the USRPs then you will have to change the verilog such that you are no longer using the digital upconverters in the AD9862 and instead implement the DUC in the FPGA. This is because there's no way to directly control the phase accumulator in the AD9862. If you can deal with a constant phase offset, then a strategy similar to what Marin used for Rx should work for Tx. Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
