Howtosignalprocessing
- What is windowing and framing of a signal?
- What does windowing do to a signal?
- Why do we need to apply windowing function to a speech signal?
- What is signal framing?
What is windowing and framing of a signal?
Frame Blocking and Windowing Algorithm
The signal s(n) of figure1 is blocked into frames of N samples and each adjacent frames are separated by M samples. Thus, the first frame is formed by the first N samples of the speech signal. The second frame is M samples after the first, overlapping it by N-M samples.
What does windowing do to a signal?
Windowing changes the shape of the signal in the time domain, as well as affecting the spectrum that you see. The following figure shows convolving the original spectrum of a signal with the spectrum of a smoothing window. Even if you do not apply a smoothing window to a signal, a windowing effect still occurs.
Why do we need to apply windowing function to a speech signal?
Windowing causes undesirable spreading of frequency components into nearby frequencies and by choosing the windowing function, we can choose how much and how far such a components are spread. In difference to classical signal analysis, speech processing applications have a range of additional requirements.
What is signal framing?
When it comes to non-stationary signals, spectral features in short parts/ sequences are of great use. Therefore, decomposing the signal into multiple ranges is the way to go about this type of features extraction. This technique is known as frame blocking or framing.
