Joint Measurement of Signal Parameters and ADC Transition Levels

The estimation of the amplitudes and phases of the components of a periodic signal based on the sequence of its quantized samples is a typical problem in instrumentation and measurement. If the signal and noise properties are taken into account, it is possible to provide more accurate estimates than those provided by typical procedures applied to quantized data, such as the least-squares estimator. In this paper, the noisy quantization of a periodic signal is considered. An estimator is described that processes the quantizer output data to provide measurements of the amplitudes and phases of the components of the input signal by applying preprocessing of the quantized sequence and by using weighted least-square estimation. The proposed estimator will also simultaneously measure the quantizer transition levels. Simulation and experimental results show that it outperforms the ordinary least-square estimator, especially when low-resolution quantization is performed and that it does not require numerical maximization of functions of several variables, as when the maximum-likelihood estimator is used.