On the Degrees of Freedom of time correlated MISO broadcast channel with   delayed CSIT
  We consider the time correlated MISO broadcast channel where the transmitter has partial knowledge on the current channel state, in addition to delayed channel state information (CSI). Rather than exploiting only the current CSI, as the zero-forcing precoding, or only the delayed CSI, as the Maddah-Ali-Tse (MAT) scheme, we propose a seamless strategy that takes advantage of both. The achievable degrees of freedom of the proposed scheme is characterized in terms of the quality of the current channel knowledge. 
Mari Kobayashi, Sheng Yang, David Gesbert, Xinping Yi
cs.IT math.IT