Mathematical description

In MIMO systems, a transmitter sends multiple streams by multiple transmit antennas. The transmit streams go through a matrix channel which consists of multiple paths between multiple transmit antennas at the transmitter and multiple receive antennas at the receiver. Then, the receiver gets the received signal vectors by the multiple receive antennas and decodes the received signal vectors into the original information. So, a MIMO system can be modeled as follows:

 y=Hx+n

where y and x are the receive and transmit vectors, respectively. In addition, H and n are the channel matrix and  the noise vector, respectively.

MIMO literature

Papers by Gerard J. Foschini and Michael J. Gans[1], Foschini[2] and Emre Telatar have shown by Telatar that the channel capacity (a theoretical upper bound on system throughput) for a MIMO system is increased as the number of antennas is increased, proportional to the minimum number of transmit and receive antennas. This basic finding in information theory is what led to a spurt of research in this area. A text book by A. Paulraj, R. Nabar and D. Gore have published an introduction to this area [3]

References

^ Gerard J. Foschini and Michael. J. Gans (January 1998). "On limits of wireless communications in a fading environment when using multiple antennas". Wireless Personal Communications 6 (3): 311�35.

^ Gerard J. Foschini (autumn 1996). "Layered space-time architecture for wireless communications in a fading environment when using multi-element antennas". Bell Labs Technical Journal 1: 41�9.

^ A. Paulraj, R. Nabar and D. Gore. Introduction to Space-time Communications.