Sinewave fit algorithm based on total least-squares method

Abstract

Sinewave fit is a fundamental task in many test and measurement systems. The characterizations of analog-digital converter and digital oscilloscopes are two examples. In this paper we present a high performance (i.e. high precision and high speed) algorithm to estimate the four parameters of a sine-wave from a sample data record. Making use of trigonometric identity, we propose a frequency estimator that turns the nonlinear estimation problem into a linear one. Thus, the difficulty of the traditional nonlinear least squares sinewave fit method is attenuated. The total least squares method Is used to estimate four parameters of a sinewave in order to make the estimation errors be minimum in the sense of l/sub 2/ norm. Simulation results exhibit that the proposed method gives superior performance over traditional ones. This new algorithm is noniterative and gives swift and consistent results.