The N-phase digital tanlock loop for tracking suppressed-carrier N-ary PSK signals

Since the early 1970s, many studies have been conducted regarding digital phase-locked loops (DPLLs). These loops represent important subsystems employed in coherent communication and tracking receivers. Lee and Un (1982) have introduced a new type of nonuniform sampling DPLL called the digital tanlock loop (DTL). The present investigation is concerned with the performance of the N-phase DTL in the presence of phase error disturbance. It has been assumed that the phase error disturbance is composed of Gaussian channel noise and modulation distortion due to bandpass filtering of the input phase shift keying (PSK) signal. The main feature of the N-phase DTL is that the phase error has linear characteristics in the modulo-2 pi/N sense as a result of using a new type of phase detector.