Applications
As mentioned in the introduction, the above techniques can be used to save the bandwidth or the filter cost.
Assume the signal look like this.
.
The dashed box is the filter, and the area of the dashed box would be the bandwidth required.
After some operations like the above example, the signal turn into the position like this.
As a result, the bandwidth was saved, since the area became smaller. Moreover, only a lowpass filter is required to recover the signal, instead of a bandpass filter.
Read more about this topic: Motions In The Time-frequency Distribution