Title :
A novel reduced-complexity MAP equalizer using soft-statistics for decision-feedback ISI cancellation
Author :
Baccarelli, E. ; Fasono, A. ; Galli, S. ; Zucchi, A.
Author_Institution :
INFOCOM Dept., Rome Univ., Italy
Abstract :
A novel version of the reduced-state Bayesian maximum a posteriori probability/decision-feedback (MAP/DF) equalizer for ISI 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 actual reliability of the (soft) decisions feeding the DF filter. Therefore, in the presented equalizer the usual (over-optimistic) assumption of error-free decisions at the input of the feedback filter is relaxed and numerical results supporting the actual effectiveness of the proposed MAP/DF equalizer are provided for the so-called high-bit-rate digital subscriber line (HDSL) test-loop # 4.
Keywords :
Bayes methods; computational complexity; decision feedback equalisers; digital subscriber lines; error statistics; interference suppression; intersymbol interference; probability; receivers; transient response; BER; Bayesian approach; HDSL test-loop; ISI channels; MAP receiver; decision-feedback ISI cancellation; decision-feedback equalizer; decision-feedback filter; high-bit-rate digital subscriber line; input error-free decisions; long impulse responses; maximum a posteriori probability; reduced-complexity MAP equalizer; reduced-state Bayesian MAP/DFE equalizer; soft decisions reliability; soft-statistics; Bayesian methods; DSL; Delay estimation; Digital filters; Equalizers; Feedback; Gaussian noise; Intersymbol interference; Multilevel systems; Tail;
Conference_Titel :
Global Telecommunications Conference, 1999. GLOBECOM '99
Print_ISBN :
0-7803-5796-5
DOI :
10.1109/GLOCOM.1999.831712
