How to speed up fast Fourier transform computation – a recurrence method

There is a strong need for new approaches to non-stationary signal analysis. These signals call for advanced time-frequency analysis techniques (see References). The recurrence procedure for calculating the Fast Fourier Transform, which enables calculations to be made several times faster, especially in the case of precise time-frequency approach, has been establish in the present contribution. This method was invented in the course of transient signal analysis carried out in the Institute of Aviation upon the aircraft impulse response in flight.