  We study a noncoherent multiple-input multiple-output (MIMO) fading
multiple-access channel (MAC), where the transmitters and the receiver are
aware of the statistics of the fading, but not of its realisation. We analyse
the rate region that is achievable with nearest neighbour decoding and
pilot-assisted channel estimation and determine the corresponding pre-log
region, which is defined as the limiting ratio of the rate region to the
logarithm of the SNR as the SNR tends to infinity.
