On 04/26/2011 11:22 AM, Khalid Jamil wrote: > Please correct me if I am wrong. I think that this random channel-channel > phase offset at each acquisition depends on when each usrp 100MHz LO locks > to 10MHz external frequency reference by PLL. How PPS will help in that > case? Unless PPS is locked somehow to 10MHz clock? >
Yes, but I strongly recommend that you get time-aligned samples working before trying to calibrate for the LO phase offsets. In your GRC flowgraph, each USRP source block will provide samples that start at a different random time that could be offset by many milliseconds. I don't think you want that? In order to get time-aligned samples from N devices, you must 1) synchronize the the time registers (seconds/ticks) across all USRP devices. You should use the PPS to do this 2) tell the devices to stream at the same time. > Is there a good example to follow, may to start with 2 or 4 channels? > There is an example that comes w/ uhd called rx_multi_samples. if you want to do this in GRC, follow the instructions in the previous email. -Josh _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
