Group delay based approach for frequency estimation in complex noises

A novel approach for frequency estimation of one-dimensional harmonics in multiplicative and additive noises is presented. To alleviate the resolution limitation of the traditional cumulant-based algorithms, group delay (GD) function is utilized. In this new approach, GD is applied to the 2nd order time-varying cumulants of harmonics in complex noises, called as the 2nd order CGD. For a given frequency estimation problem, this paper derives a simple and practical algorithm. Numerical results show that the sharp peak and high resolution property of GD preserved, which outperform some traditional methods greatly.