Modulation device, demodulation device, communication system using the same, program and method for implementing modulation and demodulation

摘要

A QAM modulation system capable of setting a number of multilevel to approximate 2^(p+0.25) (p is an integer equal to or more than 3) or 2^(p+q/n). An input data signal of 4p+1 bits are converted into four signals of p+1 bits, there being a predetermined relationship between the input data signal and the converted signals. The converted four signals are assigned to four phase planes, respectively. The four signals are time-division multiplexed and multilevel-modulated. Thereby, it becomes possible to set the number of multilevel to approximate 2^(p+0.25).