Date Added: Sep 2012
The capacity of ideal MIMO channels has an high-SNR slope that equals the minimum of the number of transmit and receive antennas. This paper shows that physical MIMO channels behave fundamentally different, due to distortions from transceiver impairments. The capacity has a finite upper limit that holds for any channel distribution and SNR. The high-SNR slope is thus zero, but the relative capacity gain of employing multiple antennas is at least as large as for ideal transceivers.