A reduced-state soft-statistics-based MAP/DF equalizer for data transmission over long ISI channels

In this contribution, a novel version of the reduced-state maximum a poster iori probability/decision-feedback (MAP/DF) equalizer for intersymbol inter ference channels with long impulse responses is presented. The main feature of the proposed equalizer is that the soft statistics generated by the MAP receiver are employed to recursively compute a suitable index of the actua l reliability of the (soft) decisions feeding the feedback filter. Therefor e, in the presented equalizer, the usual (over-optimistic) assumption of er ror-free decisions at the input of the feedback filter is relaxed and impro ved performances are experienced, especially on channels with long impulse responses.