Modulation Architecture {2m-QAM}2 over Rings of Integers for TCM

"Based on the spectral overlapping of two conventional m-QAM modulations, an {m-QAM}^2 modulation technique is performed. This architecture has shown to have better bit error performance than its equivalent M-QAM modulation. The object of this paper is to present a multilevel coding method based on a ring of integer modulo-q over an expanded trellis coded {2m-QAM}^2 modulation, to collect associated gain in terms of Eb/No. Performance curves obtained by computer simulation with spectral efficiency for coded and uncoded schemes of 5 and 6 information bit/s/Hz for three codes combination are shown."