数字调制就是把数字基带信号的频谱搬移到高频处，形成适合在信道中传输的带通信号。基本的数字调制方式有振幅键控（ASK）、频移键控（FSK）、绝对相移键控（PSK）、相对（差分）相移键控（DPSK）。在接收端可以采用想干解调或非相干解调还原数字基带信号。 -Digital modulation is the spectrum shifting to high frequency digital baseband signals, suitable for the formation of ban

Phase-shift keying (PSK) is a modulation process whereby the input signal, a binary PCM waveform, shifts the phase of the output waveform to one of a fixed number of states. The demodulation process can be divided into three major subsections, as

In a series of papers in recent years new structures for coherent M-PSK (M-ary Phase Shift Keying) receivers were suggested. These include structures for carrier phase detectors for the carrier PLL (Phase Lock Loop), carrier PLL lock dete