Title :
Turbo-equalization for multilevel modulation: an efficient low-complexity scheme
Author :
Dejonghe, A. ; Vandendorpe, L.
Author_Institution :
Commun. & Remote Sensing Lab., Univ. Catholique de Louvain, Louvain-la-Neuve, Belgium
Abstract :
This paper addresses the problem of iterative equalization and decoding (turbo-equalization) when bit-interleaved multilevel modulations are considered. The goal is to propose an efficient low-complexity solution in this context, where optimal turbo-equalization is totally untractable. Therefore, we generalize reduced-complexity soft-in/soft-out (SISO) equalizers based on the minimum mean square error (MMSE) criterion (originally proposed in a BPSK context) to this particular scheme. Performances are illustrated through simulations. We show the influence of the mapping on the signal-to-noise ratio (SNR) threshold and on asymptotic performances, and link the obtained results to iterative demodulation and decoding on an additive white Gaussian noise (AWGN) channel.
Keywords :
AWGN channels; data communication; demodulation; dispersive channels; equalisers; interleaved codes; iterative decoding; least mean squares methods; modulation coding; time-varying channels; turbo codes; AWGN channel; MMSE; SNR threshold; additive white Gaussian noise; asymptotic performance; bit-interleaved modulations; data transmission; iterative decoding; iterative demodulation; low-complexity scheme; minimum mean square error; multilevel modulation; reduced complexity SISO equalizers; signal-to-noise ratio; simulations; soft-in/soft-out equalizers; time dispersive channels; turbo equalization; AWGN; Additive white noise; Demodulation; Equalizers; Filters; Gaussian noise; Iterative decoding; Mean square error methods; Signal mapping; Signal to noise ratio;
Conference_Titel :
Communications, 2002. ICC 2002. IEEE International Conference on
Print_ISBN :
0-7803-7400-2
DOI :
10.1109/ICC.2002.997171
