An Arrangement Technique of Gray-Code Table for Signal Constellation of Modified QAM and Triangular-Shaped Signal Set
Takaya Yamazato, Shinjiro Oshita, Iwao Sasase, Shinsaku Mori · Institutional Repositories DataBase (IRDB) · 1991
An arrangement technique of Gray-code table for signal constellations of modified QAM and Triangular Shaped Signal Set is proposed. This is an optimum mapping technique for both two dimensional rectangular and hexagonal lattice-based constellations which cannot adapt the conventional Gray-code mapping. As our technique achieves most of neighboring symbols differ by one bit, the bit-error-probability (BEP) of the system becomes nearly equal to the symbol-error-probability (SEP). Furthermore, in consideration of this technique, we can have a constellation by which all neighboring symbols differ only by one bit for the rectangular lattice based constellation, but error-performances are worse than those of the original constellations because of a decrease of the corresponding decision regions.