USRP2 + UHD MIMO implementation

Hi all,

I’m working on implementation of MIMO system based on USRP2+UHD.
I used MIMO method #3, which uses 10Mhz and 1PPS external reference
Also multiple USRP2s are connected to one PC though multiple Gbit

I used multiple uhd_single_usrp_source and uhd_single_usrp_sink blocks
create MIMO.
They are also connected to traditional GR blocks with some

After aligning two timetags, synchronization is pretty much satisfied.

However, using multiple uhd_single_usrp blocks seems not clever.
I just look over uhd_mimo_source and uhd_mimo_sink block codes.

Are they just for MIMO cable setup?

ps: is there anybody who built a MIMO system with more than two antenna
using USRP2s?
I want to talk with them seriously. =)

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You may want to use the uhd_multi_usrp_blocks. They handle alignment and
synchronization in the driver. They can be used with and without the
MIMO cable. That is to say, that the MIMO cable is transparent to the