Hi Marcus and Robin,thanks for your answers, this is helpful information. I should add, that I actually tried the synchronization with an octoclock (10MHz + PPS), but it did not give me the expected results, i.e., I saw some residual frequency offsets. But maybe I screwed up at some point. Let me do some more measurements and get back to you on this.
Florian. On 04/12/2018 18:57, Marcus D. Leech via USRP-users wrote:
On 12/04/2018 10:14 AM, Florian Kaltenberger via USRP-users wrote:In addition to what Robin posted, I'll observe that the external LO port is an *additional feature* of this device.Hi there,I just discovered that in addition to the external 10MHz reference in, the USRP N310 also has external local oscilator inputs, one for each daughterboard and each TX/RX. So does that mean that in order to synchronize multiple N310 in frequency, phase, and time, it is no longer sufficient to use an octoclock to provide a 10MHz reference and PPS? If so, at what frequency do you have to drive the external LOs and at what power?Florian.You should still be able to use the external 10MHz and 1PPS ports the same way you would with a B210 or E310, since the AD9371front-end chip is similar to the AD9361 chip used in the B210 and E310.The thing about synchronizing multiple independent PLL synthesizers, though, compared to a strictly-shared-LO, is that the former will experience both phase ambiguities, and have a higher mutual phase-noise than the latter, which is why you might decide to choosethe latter. _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
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