1. A low complexity Minimum Mean Square Error (MMSE) based sequential Monte Carlo method for Multiple-Input Multiple Output demodulation, said method comprising the computer implemented steps of: receiving a plurality of signals at an array of input antennas; estimating a channel matrix and signal to noise ratio (SNR); determining a channel dependent order of demodulation processing the received signals through the use of the MMSE techniques; and detecting and decoding any transmitted symbols using deterministic sequential Monte Carlo techniques employing update separation.