Thank you M&M ! (M&M = Marcus-and-Marcus; in my dictionary 😉) On Sun, Feb 28, 2021 at 12:57 AM Marcus D Leech via USRP-users < [email protected]> wrote:
> Two X310 plus 4 UBX delivers 4x4 MIMO with an external 1PPS and 10Mhz > clock—octoclock or something else. > > The X310 does have a ref clock output, but I think it is not recommended > for use in coherent applications just because of unknown clock skew. > > > > Sent from my iPhone > > > On Feb 27, 2021, at 2:50 PM, Marcus Müller via USRP-users < > [email protected]> wrote: > > > > You're right. The whole point of the TwinRX boards is to give you > coherent channels, and > > you can build a coherent 4-channel *receiver*. > > > > However, TwinRX can't transmit, so for 4×4 MIMO, you'll need something > else. Since there's > > no dual-transmit-channel daughterboards, you'll need to coordinate the > phases of four > > different TX-capable daughterboards. Therefore, you'll need a clock > distributor like the > > octoclock. > > > > Haven't tried it in a while, but the clk and pps out of the X3x0 series > should solve that > > issue, however: you could link two USRP X3x0 that are equipped with e.g. > two UBX-160 each > > through that to get 4 coherent TX channels, and use a single USRP X3x0 > with two TwinRX as > > receiver with 4 coherent RX channels. > > > > Best regards, > > Marcus > > > > > >> On 27.02.21 15:50, Ali G. Dezfuli via USRP-users wrote: > >> Hi all, > >> When USRP X3x0 is used with TwinRX daughterboards, we can have up to 4 > rx channels. > >> (ref:AN-244, Direction Finding with the USRP™ X-Series and TwinRX™) > >> But in AN-881 (Selecting a USRP Device) in Table 4, it says that USRP > X3x0 needs > >> OctoClock for 4x4 MIMO !!! > >> I wonder when X3x0 can receive 4 channels with TwinRX, why it can NOT > be used in 4x4 > >> MIMO w/o OctoClock. > >> > >> regards, > >> AGD > >> > >> _______________________________________________ > >> USRP-users mailing list > >> [email protected] > >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > > _______________________________________________ > > USRP-users mailing list > > [email protected] > > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
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