Quantization effects in implementation of distributions from the cohen class

The paper presents an analysis of the finite register length influence on the accuracy of results obtained by the time-frequency distributions (TFDs). In order to measure quality of the obtained results, the variance of the proposed model is found, signal-to-quantization noise ratio (SNR) is defined and appropriate expressions are derived. Floating- and fixed-point arithmetic are considered. It is shown that commonly used reduced interference distributions (RID) exhibit similar performance with respect to the SNR. We have also derived the expressions establishing relationship between the number of bits and required quality of representation (defined by the SNR), which may be used for register length design in hardware implementation of TFDs.