FINITE WORD-LENGTH EFFECTS IN IMPLEMENTATION OF DISTRIBUTIONS FOR TIME-FREQUENCY SIGNAL ANALYSIS

This correspondence presents an analysis of the finite register length influence on the accuracy of results obtained by the time-frequency d istributions (TFD's). In order to measure quality of the obtained resu lts, the variance of the proposed model is found, signal-to-quantizati on noise ratio (SNR) is defined, and appropriate expressions are deriv ed. Floating- and fixed-point arithmetic are,considered, with the anal ysis of discrete random and discrete deterministic signals. It is show n that commonly used reduced interference distributions (RID's) exhibi t similar performance with respect to the SNR. We have also derived th e expressions establishing the relationship-between the number of bits and the required quality of representation (which is defined by the S NR), which may be used for register-length design in hardware implemen tation of time-frequency algorithms.