[USRP-users] Interference Nulling with N200 and MIMO cable

Josh Blum josh at ettus.com
Thu Feb 2 04:09:12 EST 2012



On 02/02/2012 12:27 AM, Yubo Yan wrote:
> Hi,
> 
>    I am working on implementation of interference nulling with USRP N200
> and MIMO-Cable. I config the first N200 device as MIMO master with:
> usrp->set_clock_source("internal",0);
> And config the second N200 device as MIMO slave with:
> usrp->set_clock_source("mimo", 1);
> usrp->set_time_source("mimo", 1);
> Finally I query the device with usrp->get_time_synchronized() , and it
> returns 1.
> But I can't achieve interference nulling with these configuration at last.
> 
> My  question is:
> 1) Does above configuration synchronize two devices properly?
> 

Correct

> 2) If I double that the two devices are not synchronized properly, how can
> I have a test just with at most four N200 devices?
> 
> 

You must share common 10 Mhz reference and PPS signal for two devices.
http://files.ettus.com/uhd_docs/manual/html/sync.html#common-reference-signals

-josh




More information about the USRP-users mailing list