  In this work, salient characteristics of a wireless communication system
deploying a great number of antennas in the base station (BS), namely Massive
MIMO system, are investigated. In particular, we found a simple and meaningful
relationship that corroborates a fundamental assumption in recent related
works: according the number of BS antennas $N$ grows, the product of the
small-scale fading channel matrix with its conjugate transpose tends to a
scaled identity, with a variability measure inversely proportional to $N$.
Furthermore, analysis of the Massive MIMO system downlink is carried out from a
bit-error-rate (BER) performance viewpoint, including some realistic adverse
effects, such as interference from neighboring cells, channel estimation errors
due to background thermal noise, and pilot contamination, which was recently
shown to be the only impairment that remains in the MIMO multicell system with
infinite number of BS antennas. Our numerical result findings show that, in the
same way as with the sum capacity, the pilot contamination also limits the BER
performance of a noncooperative multi-cell MIMO system with infinite number of
BS antennas.
