I am part of the Hydra group at UT Austin (http://hydra.ece.utexas.edu). We have developed a MIMO prototype utilizing GNU Radio & the USRP board. The physical layer for our design is based on the draft standard for IEEE 802.11n. Our current system is designed to support 2 antennas (i.e. utilizing one USRP board per node), however, we would like to extend this to 4 antennas.
We are currently following the directions on the 'USRPClockingNotes' page for synchronizing the local oscillators of two USRP boards. The only problem that remains is aligning the samples. I have been looking through the GNU Radio codebase for some insight on how to do this. I found 'usrp_multi.py' which describes how to do this for the receive chain. However, I also have to be able to align samples for the transmit chain. Does anyone have any experience with transmitting waveforms using multiple USRP boards? Specifically, do you have to go through any special process to ensure that transmitted samples are properly aligned? -- Ketan Mandke http://www.ece.utexas.edu/~mandke _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
