## PSK generation

| The simplest means of realizing unfiltered binary PSK is to switch the sign of the carrier using the data signal, causing a 0° or 180° phase shift. Just as for ASK, this method of generation is not well suited to obtaining a Nyquist filtered waveform owing to the difficulty in implementing bandpass high frequency, high Q filters.

#### If filtering is required, then linear multiplication must be employed, allowing the data stream to be pre-shaped at baseband prior to the modulation process. Because the modulation process is linear, the baseband filter shape is imposed directly onto the bandpass modulation signal.

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