Low complexity soft decision feedback equalizer for multilevel modulation

Author

He Hui-ying ; Chen Shao-chang

Author_Institution

Coll. of Electr. & Inf., Naval Univ. of Eng., Wuhan, China

Volume

2

fYear

2010

fDate

21-24 May 2010

Abstract

This letter presents a soft decision feedback equalizer (SDFE), for multilevel modulation. In contrast to common turbo principle which only uses the extrinsic information from the decoder, the SDFE can be used in the channel equalizer for calculation of the a posteriori probability (APP) by collecting information of the entire block as in maximum a-posteriori probability (MAP) algorithm. Replaced hard decision with soft decision reduces the effects of the error propagation. Meanwhile, In contrast to common soft DFE for only BPSK, The SDFE can be used for multilevel modulation, such as MPSK or QAM. Simulation results confirm the superiority of the new proposed equalizer comparing with current low complexity Turbo equalizers with hard decision for High-level modulation.

Keywords

decision feedback equalisers; feedback; maximum likelihood estimation; phase shift keying; quadrature amplitude modulation; MPSK; QAM; channel equalizer; error propagation; maximum a-posteriori probability algorithm; multilevel modulation; soft decision feedback equalizer; turbo equalizers; Binary phase shift keying; Decision feedback equalizers; Decoding; Educational institutions; Finite impulse response filter; Information filtering; Information filters; Intersymbol interference; Nonlinear filters; Probability; MMSE equalizer; decision feedback equalizer; multilevel modulation; soft feedback;

fLanguage

English

Publisher

ieee

Conference_Titel

Future Computer and Communication (ICFCC), 2010 2nd International Conference on

Conference_Location

Wuhan

Print_ISBN

978-1-4244-5821-9

Type

conf

DOI

10.1109/ICFCC.2010.5497286

Filename

5497286