need help with procedure to display time frequency distribution in Matlab

Hi I am using a matching wavelet algorithm for decomposing a signal in Matlab. I have already calculated the corresponding wavelets that add up to reconstruct the signal. To find its frequency content, I calculate the amplitude spectrum of each wavelet. Now, these wavelets have their peaks corresponding to a given instant of time (t0) . Hence, if we plot the amplitude spectrum against the corresponding t0 then in this way we can get the time frequency representation. However my doubt is that how do I spread this signal in time?

I am referring the following paper for my work. **broken link removed**
It says in this paper that to multiply the amplitude spectrum with the function G. Can someone please tell me how exactly to do this. Say I have a time X frequency matrix in which I store the values of amplitude spectrum corresponding to the different t0s. How do I proceed from here? I want to get the plot like fig 1 of this paper.