  Beam training of 802.11 ad is a technology that helps accelerate the analog
weighting vector (AWV) selection process under the constraint of the existing
code-book for AWV. However, 5G milli-meter wave (mmWave)
multiple-input-multiple-output (MIMO) system brings challenges to this new
technology due to the higher order of complexity of antennae. Hence, the
existing codebook of 11ad is unlikely to even include the near-optimal AWV and
the data rate will degrade severely. To cope with this situation, this paper
proposed a new beam training protocol combined with the state-of-the-art
compressed sensing channel estimation in order to find the AWV to maximize the
optimal data-rate. Simulation is implemented to show the data-rate of AWV
achieved by 11 ad is worse than the proposed protocol.
