Amplitude Shift Keying (ASK): Represents digital data by varying the amplitude of the carrier signal. A bit value of 1 uses high amplitude (40%), while a bit value of 0 uses low amplitude (10%).
Frequency Shift Keying (FSK): Represents digital data by varying the frequency of the carrier signal. A bit value of 1 uses a higher frequency (15 cycles/bit), while a bit value of 0 uses a lower frequency (5 cycles/bit).
Phase Shift Keying (PSK): Represents digital data by varying the phase of the carrier signal. A bit value of 1 shifts the phase by 180 degrees (π radians) compared to a bit value of 0.