  In this paper, we focus on reduced complexity full duplex Multiple-Input
Multiple-Output (MIMO) systems and present a joint design of digital transmit
and receive beamforming with Analog and Digital (A/D) self-interference
cancellation. We capitalize on a recently proposed multi-tap analog canceller
architecture, whose number of taps does not scale with the number of
transceiver antennas, and consider practical transmitter impairments for the
full duplex operation. Particularly, transmitter IQ imbalance and nonlinear
power amplification are assumed via relevant realistic models. Aiming at
suppressing the residual linear and nonlinear self-interference signal below
the noise floor, we propose a novel digital self-interference cancellation
technique that is jointly designed with the configuration of the analog taps
and digital beamformers. Differently from the state of the art, we design
pilot-assisted estimation of all involved wireless channels. Our representative
Monte Carlo simulation results demonstrate that our unified full duplex MIMO
design exhibits higher self-interference cancellation capability with less
analog taps compared to available techniques, which results in improved
achievable rate and bit error performance.
