MODULATION TYPE DISCRIMINATING METHOD, MODULATION TYPE DISCRIMINATING CIRCUIT AND DEMODULATION DEVICE

摘要

PROBLEM TO BE SOLVED: To dispense with preliminary acquisition of a feature amount for discriminating a multi-level modulation type and to determine the multi-level modulation type over a wide range having information of an amplitude direction with high discrimination accuracy.;SOLUTION: A power differential value between signal points is determined from the information of constellation of a received digital modulation signal, the power differential value is multiplied by a likelihood coefficient prepared for each modulation type to calculate signal points for likelihood comparison corresponding to respective modulation types. These signal points for likelihood comparison corresponding to the modulation types are compared with a signal point for likelihood calculation common for the modulation types predetermined using the likelihood coefficient prepared for each modulation type to determine a signal point for likelihood comparison closest to the signal point for likelihood calculation common for the modulation types, and a modulation type corresponding to the determined signal point for likelihood comparison is discriminated as a modulation type of the received digital modulation signal.;COPYRIGHT: (C)2007,JPO&INPIT