| 摘要 |
Disclosed is a QAM modulation system, in which (3p+1) or (3p+2) input signal strings, where p is an integer not less than 3, are converted by conversion means (1,2,3) into three (p+1) string signals, which are allocated to three phase planes. The converted three (p+1) string signal are time-division multiplexed by a parallel-serial conversion circuit (5) which supplies output signal to an n-ary modulator (6) which carries out multi-level modulation to realize QAM modulation in which the n may be set to approximately 2 (p+1/3) or 2 (p+2/3) . Also disclosed is a QAM modulation system, in which (4p+3) input signal strings, where p is an integer not less than 3, are converted into three (p+1) string signals, which are then allocated to three phase planes, time-division multiplexed and multi-level modulated to realize QAM modulation in which the n number may be set to approximately 2 (p+3/4) . |
