  Information transmission over a multiple-input-multiple-output (MIMO) fading
channel with imperfect channel state information (CSI) is investigated, under a
new receiver architecture which combines the recently proposed generalized
nearest neighbor decoding rule (GNNDR) and a successive procedure in the spirit
of successive interference cancellation (SIC). Recognizing that the channel
input-output relationship is a nonlinear mapping under imperfect CSI, the GNNDR
is capable of extracting the information embedded in the joint observation of
channel output and imperfect CSI more efficiently than the conventional linear
scheme, as revealed by our achievable rate analysis via generalized mutual
information (GMI). Numerical results indicate that the proposed scheme achieves
performance close to the channel capacity with perfect CSI, and significantly
outperforms the conventional pilot-assisted scheme, which first estimates the
CSI and then uses the estimated CSI as the true one for coherent decoding.
