|Subject:||Re: [Discuss-gnuradio] mimo beam forming on USRP|
|Date:||Tue, 03 Mar 2015 11:18:57 -0500|
If you use the phase-resynch feature of the SBX card, and you have common refclock and 1PPS across all your USRPs in the array,
In *general*, synthesized downconverters use fractional-N synthesizers where their starting phase after a re-tune is random with respect to any other synthesizer using the same reference clock. That's just the way fractional- N synthesis works. It happens that SBX uses an ADF4351 synthesizer, which has a (rare!) hardware feature to allow phase-resynch after tuning. In order to make this work, all SBXes in your "array" must be tuned at exactly the same time, so the timed_commands feature must be used to do the tuning.
On 2015-03-03 11:05, Pengyu Zhang wrote:
|[Prev in Thread]||Current Thread||[Next in Thread]|