Info regarding replacing USB with Infiniband Optical Fiber

GNU Radio
1

Hi,

We are working on using GNURadio for using it as RF node capable of
22/44 MIMO. All the RF nodes are connected to very big FPGA like the
one used in “Berkeley Emulation Engine (BEE)” using “Infiniband”
Optical Fiber. All the signal processing is implemented in “BEE”
hardware. We wanted to replace USB with Infiniband so that we can send
raw ADC/DAC samples to/from BEE processing engine. It would be very
helpful if some body could give us pointers on how to do this so that
we can reuse most of the design of GNUradio board.

Also, I have come across some people using two GNURadio boards for 44
MIMO. Is there a document which describes how to synchronize the LOs
of two GNURadio boards for coherent MIMO processing and program two
GNURadio boards for 44 MIMO??

Thanks,
Rohit

2

Rohit Gupta wrote:

Also, I have come across some people using two GNURadio boards for 44
MIMO. Is there a document which describes how to synchronize the LOs
of two GNURadio boards for coherent MIMO processing and program two
GNURadio boards for 44 MIMO??
Read this document, it should explain it:
gnuradio-examples/python/multi_usrp/README

(online available as
http://gnuradio.org/trac/browser/gnuradio/trunk/gnuradio-examples/python/multi_usrp/README
)

Also read:
http://gnuradio.org/trac/wiki/USRPClockingNotes

Make sure you understand the hardware requirements, have the right
cables, and set the usrp clock input and output accordingly.

I wrote the code to enable this and have experience in using it.
I you have any questions or problems getting it to work feel free to
ask.

Greetings,
Martin

3

Martin D. wrote:

helpful if some body could give us pointers on how to do this so that
we can reuse most of the design of GNUradio board.

Also, I have come across some people using two GNURadio boards for 44
MIMO. Is there a document which describes how to synchronize the LOs
of two GNURadio boards for coherent MIMO processing and program two
GNURadio boards for 44 MIMO??
I just put the desciption of how to do MIMO (MultiUSRP) in the wiki.
see:
http://gnuradio.org/trac/wiki/MultiUsrp

or
http://gnuradio.org/trac/wiki/Mimo

Greetings,
Martin

4

Hi Martin,

The document that describes MIMO configuration below suggests how 64MHz
clocks of two boards are synchronized. However, for coherent MIMO
processing, the LO, which for 802.11b band is arnd 2.4GHz has to be
synchronized. How does that happen??

Thanks,
Rohit