Patent ID: 6934342

Claim:
An automatic modulation type discrimination apparatus for receiving a reception signal having unknown communication elements and discriminating a modulation type of the reception signal, comprising: analog/digital modulation type discrimination means for extracting and analyzing a predetermined characteristic from the reception signal and discriminating whether the modulation type of the reception signal is an analog modulation type or a digital modulation type; analog modulation type discrimination means for, in a case where the reception signal is discriminated to be a signal of the analog modulation type, receiving the discriminated reception signal and discriminating whether the discriminated reception signal is an AM signal or an FM signal; the analog/digital modulation type discrimination means including discrimination means for, in a case where the modulation type of the reception signal is discriminated to be the digital modulation type, discriminating whether the reception signal is a linear modulation type signal or a nonlinear modulation type signal; linear modulation type discrimination means for, in a case where the reception signal is discriminated to be a linear modulation signal of the digital modulation type, receiving the discriminated reception signal and discriminating whether the discriminated reception signal is a 16 QAM signal, a BPSK signal, a QPSK signal, a π/4-shift QPSK signal, an 8-PSK signal, an M-ary PSK signal of multi-level exceeding 8-levels (where, M is a positive integer) or an M-ary QAM signal of multi-level exceeding 16-levels; and non-linear modulation type discrimination means for, in a case where the reception signal was discriminated to be a non-linear modulation signal by of the digital modulation type, receiving the discriminated reception signal and discriminating whether the discriminated reception signal is an M-ary FSK signal of multi-level exceeding 2-levels, a 2-FSK signal, an MSK signal or a GMSK signal, an envelope, a symbol clock and a spectrum characteristic of the reception signal being used as the predetermined characteristic.