5.--PSK-Demodulation-(Part-1)

代码说明：

  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 shown by Figure 4. First, since the incoming waveform is suppressed carrier in nature, coherent detection is required. The methods by which a phase-coherent carrier is derived from the incoming signal are termed, carrier recovery, and will be covered first.