Seonglae ChoWindow method
Sinc 같은 IIR 구현 못하니까
Window function is Rectangular function. Tradeoff (computing and accuracy) controlled by size. If signal has more data in high frequency, we need bigger size. If , then
output is convolution
Window functions
There are several window function. Ideal Rectangular function is not always optimal solution. More smoother functions are sometimes better.
Triangular function or rectangular function are not in practice because of derivation
- Bartlett function
Cosine based (Generally used because it is easy to derivate)
- Hanning function (Hann smoothing)
- Hamming function
- Blackman function
Frequency domain
- Main lobe (main beam) - important to includes
- Side lob
Window function
In signal processing and statistics, a window function is a mathematical function that is zero-valued outside of some chosen interval, normally symmetric around the middle of the interval, usually approaching a maximum in the middle, and usually tapering away from the middle. Mathematically, when another function or waveform/data-sequence is "multiplied" by a window function, the product is also zero-valued outside the interval: all that is left is the part where they overlap, the "view through the window". Equivalently, and in actual practice, the segment of data within the window is first isolated, and then only that data is multiplied by the window function values. Thus, tapering, not segmentation, is the main purpose of window functions.
https://en.wikipedia.org/wiki/Window_function
Hann function
The Hann function is named after the Austrian meteorologist Julius von Hann. It is a window function used to perform Hann smoothing. The function, with length and amplitude is given by:
https://en.wikipedia.org/wiki/Hann_function
