  The channel state information at the transmitter (CSIT) play an important
role in the performance of wireless networks. The CSIT model can be delayed and
imperfect-quality, since the feedback link has a delay and the channel state
information (CSI) feedback has distortion. In this paper, we thus characterize
the degrees-of-freedom (DoF) region of the two-user multiple-input
multiple-output (MIMO) broadcast channel with delayed imperfect-quality CSIT,
where the antenna configurations can be arbitrary. The converse proof of DoF
region is based on the enhancement of physically degraded channel. The
achievability proof of DoF region is through a novel transmission scheme
design, where the duration of each phase and the amount of transmitted symbols
are configured based on the imperfect-quality of delayed CSIT. As a result, we
show that the DoF region with delayed imperfect-quality CSIT is located between
the DoF region with no CSIT and the DoF region with delayed CSIT.
