Sliding FFT differential algorithms

Analysis of acoustic and vibration signals, which are captured in the time domain, requires their transformation to the frequency domain. In case of non stationary random signals the most adaptable algorithm is the sliding DFT. Usually, digital representation and processing of signal are made with the use of multi-bit PCM which not always meets the requirements of efficiency and technical merit. The use of differences and delta modulation for the economical representation and efficient processing of the signals needs the development of the existing algorithms as well as the working out of new simple and fast processing methods in real time The paper demonstrates these worked out methods.