The implementation of MIMO feature will double the data rate of mobile communication !!! MIMO stands for Multiple Input, Multiple Output.
MIMO basic principle :-
MIMO stands for Multiple Input, Multiple Output. Need of MIMO :- (1)High data rate :- wireless communications links with transmission rates nearing 1 Gigabit/second
Virtual Antenna Mapping (VAM):-
One drawback with such a solution is that, if separate power amplifiers (PA) are used for the two transmit antennas; the total power resource is not utilized to its full extent. Non-MIMO traffic will only utilize half of the available power, while MIMO traffic will utilize the total installed power resource. One way to overcome this problem would be to use a power balancing network (a.k.a. Virtual Antenna Mapping). In this way both power amplifiers will be fully utilized even for signals transmitted from the first antenna. VAM allows the Node-B to “appear” to the UE as if it has fewer Tx antennas than it actually has. Unbalanced power at virtual antenna ports is transformed by VAM into balanced power at physical antenna ports. The below picture explains how the data rate will be increasing in different releases of 3GPP. Currently work is going on release 8 to implement both MIMO and DUAL CELL together which will support 42 Mbps down-link and 11.52Mbps uplink speed