Accuracy of DTFT-based Sine-wave Amplitude Estimators

In this paper the accuracies of the sine-wave amplitude estimators provided by three state-of-the-art Discrete Time Fourier Transform (DTFT)-based algorithms are compared each other when a small number of cycles is acquired and the input signal is affected by wide-band noise. These algorithms allow to reduce the detrimental contribution of the spectral image component by processing specific Discrete Fourier Transform (DFT) samples using frequency-domain interpolation and the least-squares method. Two algorithms are based on two- and three-point Interpolated DFT (IpDFT) procedure, respectively. The third algorithm applies the least-squares approach to three DTFT samples in order to reduce also the contribution of wide-band noise. The robustness of the related amplitude estimators to sine-wave frequency uncertainty and wide-band noise is also investigated.