title: A new phase difference measurement algorithm for extreme frequency signals based on discrete time Fourier transform with negative frequency contribution.
abstract: For the ultralow frequency signals or adjacent Nyquist frequency signals, which widely exist in vibration engineering domain, the traditional discrete time Fourier transform (DTFT) algorithms show poor performance for phase difference measurement. To improve the accuracy of phase difference measurement for these extreme frequency signals, the phase difference measurement error of DTFT algorithm is analyzed, which indicates that the negative frequency contribution is the main cause of the bias. By considering the negative frequency contribution, a new phase difference measurement algorithm for extreme frequency signals is proposed based on DTFT, and the new formulas for phase difference calculation with different windows are derived in detail. The new algorithm has stronger inhibition of spectrum leakage and has a higher accuracy than traditional DTFT algorithms. Simulation and experimental results show that the proposed algorithm has better performance than the other DTFT algorithms.
authors: Department of Information Engineering, Logistical Engineering University, Chongqing 401311, China.
authors: Ting'ao
authors: T
authors: Shen
authors: Department of Information Engineering, Logistical Engineering University, Chongqing 401311, China.
authors: Yaqing
authors: Y
authors: Tu
authors: Department of Information Engineering, Logistical Engineering University, Chongqing 401311, China.
authors: Ming
authors: M
authors: Li
authors: Department of Information Engineering, Logistical Engineering University, Chongqing 401311, China.
authors: Haitao
authors: H
authors: Zhang