Construção Algébrica de Constelações para Codificação Wavelet

Abstract

Resumo-Este artigo propõe um método algébrico para construção de constelações para transmissão de sinais codificados por matrizes wavelet. Resultados obtidos pelo emprego de um algoritmo de otimização de constelações que preserva as simetrias naturais dos símbolos wavelet sugerem que a constelação proposta seja ótima.Palavras-Chave-Codificação de canal, Wavelets, Comunicação Digital, Constelação de sinais.Abstract-This paper presents an algebraic method for constructing constellations for wavelet coded signal transmission. Results obtained by use of an algorithm for optimizing constellations which preserves the natural symmetries of the wavelet symbols suggest that the proposed constellation is optimal.

Wavelet Channel Coding: An Algebraic Approach

“…One observed that greater probability constellation points corresponded to lower energy signals. In [15], an optimizing effort suggested that these constellations were optimal. The method proposed in [13] could be generalized to blocks of length greater than two to achieve an arbitrary spectral efficiency, however the block-tosignal mapping would not be as simple as in the case of symbols pairs.…”

“…Consider now a sequence of wavelet symbols generated by the system expressed as a polynomial y(D) as in (15). One may consider, as in [13], an alternative definition of a PGF of a sequence of wavelet symbols as…”

“…In general, WCC provides an increase in system performance at the cost of a large increase in the dimensionality of the output code. In order to counteract this drawback, some works propose constellations and increase spectral efficiency to wavelet symbols transmission, as in [8], [12], [13], [15].…”