An improved phase interpolation estimator

Abstract

The capability of time-shifting-based phase difference method against noise can be considerably improved with the increase of the translation coefficient. However, the anti-noise performance of the traditional method is limited due to the wrapped phase problem. In order to obtain high accuracy of estimate, this paper proposes an improved phase interpolation estimator which is derived in terms of the time-shifting-based phase difference method. First, the estimator utilizes three segments of signal in the time domain to build two sets of frequency estimate. Then the absolute difference of the frequency estimate between the two sets can be calculated. Subsequently, four frequency estimates with minimal absolute difference are selected. Finally, the one in four frequencies owning maximum energy is selected as the final frequency estimate. Simulation results show that the improved algorithm can overcome the wrapped phase problem to some extent and can achieve better noise immunity than traditional algorithms.