Abstract
Multiuser detection for space-time coded synchronous
multiple-access systems in the presence of independent Rayleigh fading
is considered. Under the assumption of quasi-static fading, it is
shown that optimal (full diversity achieving) space-time codes
designed for single-user channels, can still provide full diversity in
the multiuser channel. The joint optimal maximum likelihood multiuser
detector, which can be implemented with a Viterbi-type algorithm, is
derived for such space-time coded systems. Low complexity, partitioned
detector structures that separate the multiuser detection and
space-time decoding into two stages are also developed. Both linear
and nonlinear multiuser detection schemes are considered for the first
stage of these partitioned space-time multiuser receivers. Simulation
results show that these latter methods achieve performance competitive
with the single-user bound for space-time coded systems.
