Quantised sine signals estimation algorithm for portable digital signal processor based instrumentation

The principles for the development of portable instrumentation equipment (multimeters, frequency meters, etc.) using quantised sine signals, with a common unknown fixed frequency, and an estimation algorithm implemented on digital signal processors (DSPs) are described. An unknown internal sine signal is generated. For measurements, analog to digital converters (ADCs) acquire multiple samples of sine signals, which are quantised and transmitted to the DSP. A precise quantised sine signal, with a common unknown fixed frequency, signal estimation algorithm, for DSP-based instrumentation, is presented. An iterative process is performed to obtain amplitudes, phases, dc components, common frequency and to control the ADC number of bits. Final solutions depend on the initial values, obtained using different classical estimation algorithms. The accuracy of the initial values of iterations and the number of used points have a large influence on the speed of convergence. The algorithm stops when quantisation conditions are satisfied.