QAM communication system.

摘要

A digital communication system using a QAM signal and a honeycomb constellation multilevel signal. The digital communication system includes a modulator (100a) having a unit (101) transforming in-phase and quadrature-phase data (D(i), D(q)) arranged in a quadrature lattice constellation into two data arranged in a honeycomb constellation, and a unit (102) amplitude-modulating the transformed data, and a demodulator (200a) for demodulating a transmitted signal output from the modulator.