The combined prior information in MMSE turbo equalization with preprocessor

In minimum mean squared error (MMSE) based turbo equalization, the decoder´s extrinsic information is used as the MMSE equalizer´s prior information. In order to improve the performance, the combined prior information which consists of the whole decoder´s extrinsic information and the partial decoder´s full information in the last iteration, is used by the MMSE equalizer. Meanwhile, the MMSE equalizer is lead by matched filter as a preprocessor to reduce the complexity. The extrinsic information transfer (EXIT) chart analysis and simulation results show that the performance of the proposed scheme is much better than that of the conventional turbo equalizer.