Performance of the Time-Delay Digital Tanlock Loop as PM Demodulator in Gaussian Noise

In a previous work we proposed a phase-lock structure called the time-delay digital tanlock loop (TDTL). This digital phase-locked loop (DPLL) performs nonuniform sampling and utilizes a constant time-delay unit instead of the constant 90-degrees phase-shifter used in conventional tanlock structures. The TDTL reduces the complexity of implementation and avoids many of the practical problems associated with the analog or digital Hilbert transformer, while it preserves the most important features of the conventional DTL (CDTL). In this paper we investigate the performance of the TDTL in demodulating phase- and frequency-modulated signals in the presence of additive Gaussian noise.