瞬时频率的解释和瞬时频率估计算法的介绍，回顾目前存在的一些瞬时频率估计算法以及作者提出的新的算法-This paper, which addresses the important issue of estimating

the instantaneous frequency (IF) of a signal, is a sequel to the

paper which appears in this issue, and dealt with the concepts

relating to the IF. In this paper the concept of IF is extended to

be able to cope with discrete time signals. The specific problem explored is that of estimating the IF of frequency modulated

(FM) discrete-time signals imbedded in Gaussian noise. There are many well established methods for estimating the IF-these methods include differentiation of the phase and smoothing thereof adaptive frequency estimation techniques such as the phase locked loop (PLL), and extraction of the peak from time-varying spectral

representations. More recently methods based on a modeling of the signal phase as a polynomial have been introduced. All of these methods are reviewed, and their performances are compared on both simulated and real data. Guidelines are

given as to which estimationmethodshould be used for