An introduction to dither

In engineering, as in life, it is sometimes necessary to "harm" something in order to help it. When windowing data before calculating its discrete Fourier transform (DFT), we corrupt "pristine" data to minimize certain types of distortion to the DFT. It has been shown that sometimes it is beneficial to add some noise to a signal, to "corrupt" it, before quantizing and digitizing the signal by passing it through an analog to digital converter (ADC). (See [1], [2], and [3] and the references therein.) In this introduction, we see how and why one adds noise to certain signals.