  We consider the massive Multiple Input Multiple Output (MIMO) diversity
channel affected by independent and identically distributed Rayleigh fading,
with linear processing at both transmitter and receiver sides, and analyze the
outage capacity for large number of antennas. We first discuss the classical
Single Input Multiple Output (SIMO) diversity channel that uses Maximal Ratio
Combining (MRC) or Selection Combining (SC). For MRC, a numerical computation
and a Gaussian Approximation (GA) are considered, whereas for SC an exact
evaluation is possible. The analysis is then straightforwardly extended to the
Multiple Input Single Output (MISO) system that uses Maximal Ratio Transmission
(MRT) or transmit antenna selection. The general Multiple Input Multiple Output
(MIMO) system that pursues full diversity is finally considered, with both
optimal linear processing and simple antenna selection at both transmitter and
receiver. If the number of antennas is sufficiently large on at least one side,
the outage capacity of each considered diversity channel approaches that of a
suitable reference Additive White Gaussian Noise (AWGN) channel with properly
defined Signal-to-Noise Ratio (SNR), which provides a performance benchmark.
This conclusion is valid for large but realistic number of antennas compatible
with the assumption of independent fading.
