Thus PSK systems require less transmitted power for a given probability of

error than ASK or FSK systems.

Synchronous detection of PSK signals is required,due to the absense of a large

carrier component.Carrier recovery is there for emore complex and expensive.

DPSK systems are often a good compromise,offering simpler circuit ryata

small performance cost.The PSD of a PSK waveform is centered around!c,

and has an identical shape to that of the double side band modulating spectral

density