A method and device employing an iterative MMSE equalization-decoder soft information exchange decoding. The method uses a MMSE equalizer which receives and outputs soft information. The equalizer exchanges soft information with a soft input soft output decoder, preferably an error correction decoder. The nature of the equalizer permits solutions beyond one-dimensional data streams and permits solutions for long channel lengths and multi-dimensional data since the solution is not a function of the channel impulse response.