  Millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO)
systems have been considered as one of the primary candidates for the fifth
generation (5G) and beyond 5G wireless communication networks to satisfy the
ever-increasing capacity demands. Full-duplex technology can further enhance
the advantages of mmWave massive MIMO systems. However, strong
self-interference (SI) is the major limiting factor in full-duplex technology.
Hence, this paper proposes a novel angular-based joint hybrid
precoding/combining (AB-JHPC) technique for the full-duplex mmWave massive-MIMO
systems. Our primary goals are listed as: (i) improving the self-interference
cancellation (SIC), (ii) increasing the intended signal power, (iii) decreasing
the channel estimation overhead, (iv) designing the massive MIMO systems with a
low number of RF chains. First, the RF-stage of AB-JHPC is developed via slow
time-varying angle-of-departure (AoD) and angle-of-arrival (AoA) information. A
joint transmit/receive RF beamformer design is proposed for covering
(excluding) the AoD/AoA support of intended (SI) channel. Second, the BB-stage
of AB-JHPC is constructed via the reduced-size effective intended channel.
After using the well-known singular value decomposition(SVD) approach at the
BB-stage, we also propose a new semi-blind minimum mean square error (S-MMSE)
technique to further suppress the residual SI power by using AoD/AoA
parameters. The numerical results demonstrate that the SI signal is remarkably
canceled via the proposed AB-JHPC technique. It is shown that AB-JHPC achieves
85.7 dB SIC and the total amount of SIC almost linearly increases via antenna
isolation techniques. We observe that the proposed full-duplex mmWave massive
MIMO systems double the achievable rate capacity compared to its half-duplex
counterpart as the antenna array size increases and the transmit/receive
antenna isolation improves.
