초록 ▼

A modulation and demodulation method for communication between a transmitting side and a receiving side includes a step of at the transmitting side, producing a modulating signal, an amplitude ratio of a current instantaneous amplitude of the modulating signal and an instantaneous amplitude at n sym

A modulation and demodulation method for communication between a transmitting side and a receiving side includes a step of at the transmitting side, producing a modulating signal, an amplitude ratio of a current instantaneous amplitude of the modulating signal and an instantaneous amplitude at n symbols previously in time (n is a natural number) of the modulating signal being set to correspond to a code to be transmitted, a step of at the transmitting side, modulating a carrier with a radio frequency or an intermediate frequency by the modulating signal to provide and transmit a modulated signal, a step of at the receiving side, receiving the transmitted modulated signal to provide a received signal, and a step of at the receiving side, deciding the transmitted code from an amplitude ratio of an instantaneous amplitude of a signal point in a signal space and an instantaneous amplitude of the signal point in the signal space n symbols previously in time with respect to the received signal. A first amplitude ratio value equal to or smaller than 1 and a second amplitude ratio value equal to or greater than 1 are prepared. The amplitude ratio is selected one of the first and second amplitude values so as to prevent the modulating signal from converging to zero and from diverging.

대표청구항 ▼

[ What is claimed is:] [16.] A demodulator comprising:an amplitude and absolute phase detection means for detecting an instantaneous envelope level in a signal space and an absolute phase in the signal space of a received signal;a n-symbol delay means for providing an instantaneous envelope level of

[ What is claimed is:] [16.] A demodulator comprising:an amplitude and absolute phase detection means for detecting an instantaneous envelope level in a signal space and an absolute phase in the signal space of a received signal;a n-symbol delay means for providing an instantaneous envelope level of said received signal at n symbols previously in time (n is a natural number);an amplitude ratio calculation means for calculating an amplitude ratio of an instantaneous amplitude in a signal space and an instantaneous amplitude in the signal space n symbols previously in time from said instantaneous envelope level and said instantaneous envelope level at n symbols previously; anda decision means for deciding a code transmitted in accordance with said absolute phase and said calculated amplitude ratio.