What's OFDM-MIMO ?

 Multiple Input Multiple Output (MIMO)

     One building block for next-generation wireless access, MIMO (multiple-input, multiple-output), is an advanced antenna technology that can carry 4 to 5 times more data traffic than today’s most advanced UMTS-HSDPA-ready (3G) networks. A network design incorporating MIMO technology provides the scalability needed to quickly deliver multimedia content to the mass market. With MIMO, for example, a ½ megabit picture can be downloaded in a half second or a 30-megabit video in half a minute. 

We know that there are 4 types : SISo , SIMO , MISO and MIMO  


SISo : Single i/p , Single O/p
SIMO : Single i/p , Multi o/p
MISO : Multi i/p , Single o/p

                       Th figure below show us the different : 

So now back to MIMO , MIMO works by creating multiple parallel data streams between the multiple transmit and receive antennas (see figure below). Using the multi-path phenomenon, it can differentiate the separate signal paths from each MIMO antenna. Thinking back to the highway example, MIMO effectively adds several new highways.

                                                    The figure shows 2 × 2 MIMO