Multi-channel soft decision feedback with application to multi-user CDMA

A new approach based on joint entropy maximization (JEM) is taken in order to introduce a soft decision device in a decision feedback equalizer (DFE) for a multi-input, multi-output communication channel. Previously reported results for single channel DFE are extended to the multi-channel case and the appropriate choice of the soft decision mapping is discussed. Additionally, the DF filter with soft decision is applied for interference suppression in code division multiple access (CDMA) systems. Simulation results show that the blind algorithms with the soft decision outperform the one with the hard decision.