  In this letter, we proposed a shared-antenna full-duplex massive MIMO model
for the multiuser MIMO system. This model exploits a single antenna array at
the base station (BS) to transmit and receive the signals simultaneously. It
has the merits of both the full-duplex system and the time-division duplex
(TDD) massive MIMO system, i.e., the high spectral efficiency and the channel
reciprocity. We focus on the zero-forcing (ZF) and the maximal-ratio
transmission/maximal-ratio combining (MRT/MRC) linear processing methods, which
are commonly used in the massive MIMO system. As the main finding, we prove
that the self-interference (SI) in a shared-antenna full-duplex massive MU-MIMO
system can be suppressed in the completely dependent uplink and downlink
channels when the number of antennas becomes large enough.
