High-precision frequency estimation algorithm based on double recursion adaptive filtering

According to problems existed in the previous research studies about the detection and frequency estimation of a line-spectrum signal, this paper proposes a signal frequency extraction algorithm which has double recursion features, based on the analysis of adaptive instantaneous frequency estimation algorithm. The high-precision frequency estimation algorithm was based on a double recursion adaptive filter grouped into a circle. By comparing the instantaneous frequency sequence's variances of different adaptive filters, update the filter's center frequency and bandwidth, in order to get the optimal filter output. The simulation analysis confirmed that, in comparison to the traditional methods, this method provides a better noise immunity and frequency tracking capability, as well as controls the frequency estimation accuracy.