MIMO Channel Gain Mechanisms Relative to SISO Channel

In contrast to the rest of wireless communication technologies, Multiple-Input Multiple-Output (MIMO) technology enjoys different gain mechanisms that make it very attractive for reliable high data rate wireless communications. This paper presents a study on these gain mechanisms with particular emphasize on the case of high average receive Signal to Noise Ratio (SNR) where the MIMO system deployment is most promising. They write the MIMO channel capacity in terms of gains relative to a Single-Input Single-Output (SISO) wireless channel. Doing so, spatial multiplexing gain and power gain of MIMO wireless channels become more insightful.