Abstract
Radio link adaptivity will be a key feature of the air interfaces of future mobile communication systems. This adaptivity includes techniques such as fast scheduling, hybrid ARQ, transmit diversity and adaptive modulation and coding. The performance of adaptive modulation generally suffers from the power inefficiencies of multilevel modulation formats. This is due to the variations in bit reliabilities caused by the bit-mapping onto the signal constellation. This article presents a concept, called constellation rearrangement (CoRe), which improves the multilevel modulation power efficiency by the joint application with transmit diversity schemes. It is shown by a theoretical analysis for 16-QAM that the presented concept can equalize variations in bit reliabilities by employing different mapping rules for the transmission over the diversity branches. This significantly improves the receiver block error rate performance and, hence, the performance of the adaptive modulation and coding. This is proven by simulations at link-level in a multicarrier CDMA system for AWGN and fading channels employing turbo coded transmission.
Similar content being viewed by others
References
A. Burr, Modulation and Coding for Wireless Communications, Prentice-Hall: Essex, UK, 2001.
F. Xiong, Digital Modulation Techniques, Artech House: Norwood, MA, 2000.
C. Wengerter, A.G.E. von Elbwart, E. Seidel, G. Velev and M.P. Schmitt, "Advanced hybrid ARQ technique employing a signal constellation rearrangement", IEEE VTC 2002 Fall, Vol. 4, pp. 2002–2006, 2002.
3GPP, "Technical specification 25.212, multiplexing and channel coding (FDD)", v. 5.3.0, December 2002, http://www.3gpp.org.
C. Berrou, A. Glavieux, and P. Thitimajshima, "Near Shannon limit error-correcting coding and decoding: Turbo-codes", IEEE ICC 1993, pp. 1064–1070, 1993.
S. Le Goff, A. Glavieux, and C. Berrou, "Turbo-codes and high spectral efficiency modulation", IEEE SUPERCOMM/ ICC 1994, Vol. 2, pp. 645–649, 1994.
R. Pyndiah, A. Picart, and A. Glavieux, "Performance of block Turbo coded 16-QAM and 64-QAM modulations", IEEE GLOBECOM 1995, Vol. 2, pp. 1039–1043, 1995.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wengerter, C., von Elbwart, A.G.E. & Seidel, E. Constellation Rearrangement: Enhancement for Multilevel Modulation Formats and Transmit Diversity. Wireless Personal Communications 29, 35–45 (2004). https://doi.org/10.1023/B:WIRE.0000037568.22190.32
Issue Date:
DOI: https://doi.org/10.1023/B:WIRE.0000037568.22190.32