Amplitude and phase-shift keying

Amplitude and phase modulation (English amplitude and phase - shift keying) or asymmetric phase modulation (English asymmetric phase shift keying ), ( ALCC ) is a digital modulation, which encodes the data by changing the amplitude and phase angle of a carrier. This procedure combines amplitude shift keying ( ASK) and phase shift keying ( PSK ) to expand the codeword matrix. This method can also be regarded as a subset of the quadrature amplitude modulation (QAM). The advantages over the common ( orthogonal ) QAM is a smaller number of amplitude, which leads to less error in the use of nonlinear amplifiers, and the smaller maximum amplitude, which allows a better utilization of power.