.. Nevermind on the final point, and kudos to Ettus for providing a very easy approach for rebuilding the on-radio MPM libraries here: https://files.ettus.com/manual/page_usrp_e3xx.html#e3xx_software_dev_mpm_native
From: David Raeman <da...@synopticengineering.com> Sent: Wednesday, January 11, 2023 1:45 PM To: usrp-users@lists.ettus.com Subject: [USRP-users] Changing frequency drift across E320 radios with common clock Hello, I'm working on a project that involves phase-coherent reception across multiple E320 radios. I'm currently operating with a common clock (provided by an Octoclock) and cabled RF connections. I understand there will be some unknown phase offset between radios which changes across power cycles and re-tunes, but I'm expecting that relationship to be otherwise stable (neglecting temperature and other environmental effects). I'm trying to track down what I think is a frequency difference between receive radios which changes between across RX captures, even though I do not disconnect or re-tune between (although I do use the same port for TX between these receptions). I disable the I/Q balance tracking for the receive channels. Beyond that, I'm wondering whether the AD9361 has other active tracking loops or anything that happens between RX/TX turnaround which would lead to this behavior. This same experiment/codebase did not have this discrepancy when run on N200/SBX radios some time ago, which is why I suspect some mechanism in the RFIC. On a related note, I'm also looking at how to peek/poke the AD9361 register interface on an MPM radio. As far as I can trace, the data flow is something like: * Application calls into the UHD API * UHD sends an RPC requests to the radio * A Python service on Zynq PS handles the RPC request and calls into native libusrp-periphs.so library * libusrp-periphs.so library includes exported symbols from the 9361 C++ driver So in order to make any changes to the AD9361 driver on the E320, I'd need to cross-compile the UHD C++ libraries on the radio. Is there an easier path I'm overlooking, or barring that, any documentation on the appropriate environment/toolchain/procedure to rebuild the libraries on the radio? Thanks, -- David Raeman Synoptic Engineering
_______________________________________________ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
