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 detectors, symbol timing error detectors,

symbol synchronization PLL lock detectors, carrier and

symbol PLL loop filters, and SNR (Signal to Noise Ratio)

estimators