Performance Analysis of MIMO Wireless Communications over Fading Channels - A Review

Multiple Input Multiple Output (MIMO) technology uses multiple antennas at the both link ends and does not need to increase additional transmit power and spectrum, leading to promising link capacity gains of several-fold increase in spectrum efficiency. Increased capacity can be achieved by introducing additional spatial channels that are exploited by using coding such as space-time coding (STC). The spatial diversity improves the link reliability by reducing the adverse effects of link fading and shadowing. In this article, we survey environmental factors that affect MIMO capacity. These include channel complexity, external interferences, and channel estimation errors. With the use of MIMO communication techniques, multipath need not be a hindrance and can be exploited to increase potential data rates and simultaneously improve robustness of the wireless links. This review article provides a detailed explanation of this MIMO technology and explains how such benefits can be achieved using this technological breakthrough.