  In this paper, we investigate the design of multiple-input multiple-output
single-user precoders for finite-alphabet signals under the premise of
statistical channel-state information at the transmitter. Based on an
asymptotic expression for the mutual information of channels exhibiting antenna
correlations, we propose a low-complexity iterative algorithm that radically
reduces the computational load of existing approaches by orders of magnitude
with only minimal losses in performance. The savings increase with the number
of transmit antennas and with the cardinality of the signal alphabet, making it
possible to supports values thereof that were unwieldy in existing solutions.
