Mobile Technology 

MIMO(Multiple Input Multiple Output) is a technology to transmit multiple streams(layers) of data simultaneously. Of course, the purpose of this technique is to increase the throughput.

Even though MIMO is defined in 3GPP for 3G(HSPA MIMO), its real application started from LTE from the day 1 and will be the most crucial feature (especially in mmWave operation) in 5G.

• For 5G MIMO : See here, here, here, here, here
• For 4G MIMO : See here, here  
• For 3G MIMO : Note Not Ready Yet