Title :
Optimum asymmetric constellation design for trellis-coded modulation over gaussian channels
Author :
Zhang, Xiaoxin ; Zhao, Yuping ; Zou, Li
Author_Institution :
State Key Lab. of Adv. Opt. Commun. Syst. & Networks, Peking Univ., Beijing, China
fDate :
7/1/2009 12:00:00 AM
Abstract :
This letter studies the optimization of asymmetric constellations for trellis-coded modulation (TCM). Unlike the conventional criterion of maximizing the free Euclidean distance, the criterion here is to minimize the bit error rate (BER) of TCM systems. The letter presents an easy way to derive the BER upper bound for any TCM codes, and proposes the method for designing optimum asymmetric constellations by minimizing the bound. The given method can be applied to TCM systems with arbitrary state numbers. Numerical results verify that all the codes designed by the proposed method achieve better BER performance than symmetric ones.
Keywords :
Gaussian channels; error statistics; trellis coded modulation; BER performance; Euclidean distance; Gaussian channel; bit error rate; optimum asymmetric constellation design; trellis-coded modulation; Bit error rate; Convolution; Convolutional codes; Design methodology; Euclidean distance; Gaussian channels; Hamming distance; Quadrature phase shift keying; Signal mapping; Upper bound; Asymmetric constellation, bit error rate (BER), Euclidean distance, Hamming distance, trellis-coded modulation (TCM).;
Journal_Title :
Communications Letters, IEEE
DOI :
10.1109/LCOMM.2009.090513
