  Studies of the MISO Broadcast Channel (BC) with delayed Channel State
Information at the Transmitter (CSIT) have so far focused on the sum-rate and
Degrees-of-Freedom (DoF) region analysis. In this paper, we investigate for the
first time the error rate performance at finite SNR and the
diversity-multiplexing tradeoff (DMT) at infinite SNR of a space-time encoded
transmission over a two-user MISO BC with delayed CSIT. We consider the
so-called MAT protocol obtained by Maddah-Ali and Tse, which was shown to
provide 33% DoF enhancement over TDMA. While the asymptotic DMT analysis shows
that MAT is always preferable to TDMA, the Pairwise Error Probability analysis
at finite SNR shows that MAT is in fact not always a better alternative to
TDMA. Benefits can be obtained over TDMA only at very high rate or once
concatenated with a full-rate full-diversity space-time code. The analysis is
also extended to spatially correlated channels and the influence of transmit
correlation matrices and user pairing strategies on the performance are
discussed. Relying on statistical CSIT, signal constellations are further
optimized to improve the error rate performance of MAT and make it insensitive
to user orthogonality. Finally, other transmission strategies relying on
delayed CSIT are discussed.
