  In this paper, we study the beam-based training design jointly with the
transmission design for hybrid massive antenna single-user (SU) and
multiple-user (MU) systems where outage probability is adopted as the
performance measure. For SU systems, we propose an interleaved training design
to concatenate the feedback and training procedures, thus making the training
length adaptive to the channel realization. Exact analytical expressions are
derived for the average training length and the outage probability of the
proposed interleaved training. For MU systems, we propose a joint design for
the beam-based interleaved training, beam assignment, and MU data
transmissions. Two solutions for the beam assignment are provided with
different complexity-performance tradeoff. Analytical results and simulations
show that for both SU and MU systems, the proposed joint training and
transmission designs achieve the same outage performance as the traditional
full-training scheme but with significant saving in the training overhead.
