All-Phase FFT (apFFT) Multi-Frequency Testing Program with Time-Shift Phase Difference Method

All-Phase FFT (apFFT) is an enhanced fast Fourier transform algorithm that incorporates comprehensive phase preprocessing on top of conventional FFT, significantly improving spectral analysis accuracy. The time-shift phase difference method integrates phase information for frequency correction, and their combination enables precise estimation of signal parameters including amplitude, frequency, and phase.

The testing program includes 5 built-in test signals with different frequencies, simulating complex signal analysis scenarios. Compared to traditional FFT algorithms, apFFT demonstrates superior resistance to spectral leakage, while the time-shift phase difference method effectively overcomes the fence effect. This combination achieves near-theoretical-limit measurement precision in simulation tests.

Key implementation aspects include: 1) All-phase data preprocessing to eliminate endpoint effects through windowing and overlapping techniques; 2) Precise frequency correction using phase difference calculations between time-shifted sequences; 3) Multi-frequency signal separation processing technology for independent parameter extraction. These integrated techniques make the program particularly suitable for applications requiring high-precision parameter estimation, such as vibration analysis, acoustic measurement, and other signal processing fields.