Quadrature Amplitude Modulation


quadrature amplitude modulation

[¦kwäd·rə·chər ‚am·plə‚tüd ‚mäj·ə′lā·shən] (communications) Abbreviated QAM. Quadrature modulation in which the two carrier components are amplitude-modulated. A digital modulation technique in which digital information is encoded in bit sequences of specified length and these bit sequences are represented by discrete amplitude levels of an analog carrier, by a phase shift of the analog carrier from the phase that represented the previous bit sequence by a multiple of 90°, or by both.

Quadrature Amplitude Modulation

(QAM) A method for encoding digital data in an analog signalin which each combination of phase and amplitude representsone of sixteen four bit patterns. This is required for faxtransmission at 9600 bits per second.