Tx Rate of OFDM

Hi,

Could somebody tell me the maximal rate which can be acheived using OFDM
in
USRP currently? Is this achieved by using benchmark_ofdm_tx(rx).py?

Another question is that is there any source code on MIMO+OFDM
available? I
noticed that USRP can support MIMO, but I didn’t find any code on
MIMO+OFDM.
Thanks very much!

Best,
Jin