Title :
High-order optimum hexagonal constellations
Author :
Murphy, Charles D.
Author_Institution :
Lab. of Signal Process., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
Bandwidth-limited high-rate digital communications systems use large constellations such as M-ary QAM, M∈{64, 128, 256, 512, 1024}. These square or cross-shaped constellations, though easy to implement, do not pack the symbols together as efficiently as possible, and besides are symmetric when the symbols are equiprobable and independent, so that no channel information is available from blind third-order statistics of the channel outputs. We develop high-order “optimum” hexagonal constellations, some of which are naturally asymmetric, and all of which can be modified to be asymmetric without exceeding the peak and average power levels of the corresponding M-ary QAM constellations
Keywords :
bandlimited communication; digital communication; higher order statistics; modulation; optimisation; M-ary QAM; M-ary QAM constellations; average power level; bandwidth-limited communications systems; blind third-order statistics; channel outputs; cross-shaped constellation; equiprobable symbols; high-order optimum hexagonal constellations; high-rate digital communications systems; independent symbols; large constellations; peak power level; square-shaped constellation; Bit rate; Equalizers; Filters; Gaussian noise; Intersymbol interference; Laboratories; Probability; Quadrature amplitude modulation; Signal processing algorithms; Statistics;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2000. PIMRC 2000. The 11th IEEE International Symposium on
Conference_Location :
London
Print_ISBN :
0-7803-6463-5
DOI :
10.1109/PIMRC.2000.881407
