Choi–Williams distribution function

Choi–Williams distribution function is one of the members of Cohen's class distribution function.

This distribution function adopts exponential kernel to suppress the cross-term.

However, the kernel gain does not decrease along the

axes in the ambiguity domain.

Consequently, the kernel function of Choi–Williams distribution function can only filter out the cross-terms that result from the components that differ in both time and frequency center.