Adaptive DPSD algorithm with automatic tracking of reference signal frequency

Many applications concerning the estimation of the parameters of the sinusoidal signal under the condition of ultra-low SNR (-30 to -60 dB) are realized with Phase Sensitive Detection (PSD). It is necessary for a traditional analogue PSD to have a reference signal that has the same frequency as the measured sinusoidal signal, but in many cases such a reference signal is difficult to obtain. An adaptive DPSD (digital phase sensitive detector) algorithm with the automatic tracking of the reference signal frequency is presented in this paper. The frequency response and the realization of the DPSD algorithm are studied. Simulation results coincide with the theoretical analysis. The proposed algorithm can be used to estimate the parameters of a sinusoidal signal under the condition of ultra-low SNR (-30 to -60 dB).