This paper considers the problem of uplink transmission over multiple-input multiple-output (MIMO) channels affected by slow frequency-nonselective uncorrelated and correlated Rayleigh fading. We consider the case when channel state information, corrupted by estimation errors, is available at the receiver only. In this setting, we generalize the derivation of our previously proposed linear-complexity MIMO signal detector and derive closed-form expressions for the distribution of its soft outputs and the approximate symbol error probability. Based on this soft decision detector, we consider a turbo-coded MIMO uplink architecture with iterative processing, which enables performance within 1.6 to 2.8 dB of the ergodic capacity limit and outperforms the T-BLAST (turbo-Bell Laboratories layered space-time) system by about 10 dB at bit error rates of 10 − 5 . The presented results illustrate that this linear-complexity MIMO signal detector is highly robust to channel estimation errors.