Joint optimization of signal constellation bit labeling for bit-interleaved coded modulation with iterative decoding

Author

Muhammad, Nabil Sven ; Speidel, Joachim

Author_Institution

Inst. of Telecommun., Univ. of Stuttgart, Germany

Volume

9

Issue

9

fYear

2005

fDate

9/1/2005 12:00:00 AM

Firstpage

775

Lastpage

777

Abstract

We optimize signal constellation and bit labeling for bit-interleaved coded modulation with iterative decoding (BICM-ID). Target is to minimize bit error rate floor and signal to noise ratio for the turbo cliff. Various optimal non-orthogonal 16-QAM mappings are presented. An improvement of 0.2 dB is shown compared to state of the art orthogonal QAM-constellation with approx. the same error floor. To obtain these results, we derive the probability density function of extrinsic L-values of the demapper for perfect a priori knowledge in closed form. This allows fast computation of mutual information in the EXIT chart.

Keywords

error statistics; interleaved codes; iterative decoding; minimisation; modulation coding; probability; quadrature amplitude modulation; turbo codes; BICM-ID; EXIT chart; bit error rate; bit-interleaved coded modulation; iterative decoding; minimization; nonorthogonal 16-QAM mapping; probability density function; signal constellation optimization; turbo cliff; Bit error rate; Constellation diagram; Gaussian noise; Interleaved codes; Iterative decoding; Labeling; Modulation coding; Probability density function; Signal to noise ratio; Utility programs;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2005.09013

Filename

1506699