A major technological breakthrough in improving the
transmission reliability of wireless links was facilitated by the
employment of multiple antennas at the transmitter and receiver.
The concept of employing multiple antennas which demonstrated a
significant increase of the achievable capacity without requiring
any extra bandwidth or power. Compared to SISO systems ,MIMO
systems are capable of combating the deleterious effects of
multipath fading, which is one of the main challenges in the design
of wireless communication systems. MIMO systems may be
classified into different groups according to a range of different
criteria. we show the benefits of the MIMO systems, by classified
MIMO techniques into five categories according to their functions.
and also we are classified MIMO techniques into two categories
(open loop and closed loop) according to CSIT. Also we show the
trade-off between Spatial Diversity, Spatial Multiplexing, and
finally we study how we are employing multiple antennas in the
communication of Unmanned Aerial Vehicle (UAV) systems, so
we are studying the conditions of the ground station and the heights of the UAV, Moreover, the results from the simulation (matlab program ) points to trade-off between Spatial Diversity, Spatial Multiplexing, and conditions of the ground station and the heightsof the UAV.
