The pre-processing required at the transmitter side by many MIMO (Multi-Input, Multi-Output) schemes can lead to signals with substantial envelope fluctuations, making them very prone to nonlinear distortion effects. These nonlinear distortion effects can lead to significant performance degradation and signals with high irreducible error floor when conventional receivers are employed. However, the nonlinear distortion has information on the transmitted signals than can be employed to improve the performance, provided that an optimum receiver is employed. Nevertheless, the huge complexity of optimum receivers precludes its use in most practical scenarios. In this paper we consider MIMO schemes with strong nonlinear effects at the transmitter side and we propose an iterative receiver that is able to cope with nonlinear effects, allowing excellent performance even with strong nonlinear distortion effects. In fact, our results show that MIMO schemes with strong nonlinear effects can even perform better than linear MIMO system.