Iterative detection for a MIMO (multiple-input, multiple-output) wireless
communications system uses multiple stages for interference cancellation
refinements. Detection is determined by maximizing signal to noise plus
interference ratios. Equalization matrix updating uses a
matrix-inversion-free recursion. For P transmitter antennas and Q
receiver antennas, the soft symbol vector estimates are z=Fr-Gs.sup.hard
with F a P.times.Q IMMSE detector, r the received Q vector, and G a
P.times.P interference canceller with s.sup.hard hard decisions of prior
symbols and iterations.