Welcome Guest ( Log In | Register )

FFT Windowing
post Jun 5 2003, 17:42
Post #1

Group: Members
Posts: 97
Joined: 14-April 02
Member No.: 1781

I am in the process of trying to understand FFT analysis as it pertains to audio, and I have come across the concept of FFT windowing. Am I understanding it correctly that the main use of FFT windowing is to get better results in the frequency domain (ex. minimizing Gibbs Phenomenon) ?

It seems that one of the most common window functions used is the Hamming window. If I want to use the Hamming window do I just apply and upward slope from the first sample in my data chunk to the center sample and a downward slope from the center sample to the last sample? (This is what the graph in front of me shows) Or is there an explicit mathematical method I am not aware of?

Edit: Is the Hamming window good for complex signals too? (the example I read about had only one frequency involved)

This post has been edited by RiskyP: Jun 5 2003, 17:43
Go to the top of the page
+Quote Post
Start new topic
post Jun 5 2003, 21:19
Post #2

Group: Members
Posts: 158
Joined: 30-August 02
Member No.: 3236

A frequency bin is simply an FFT output value which represents a specific frequency. If you perform, for instance, a 16-point FFT, you're computing 8 frequency components equally spaced between DC and Nyquist (Fs/2). You now have an 8-frequency spectrum analysis of the signal. Frequencies in the source data that fall outside the 8 frequency bins or slots bleed onto adjacent bins. In order to reduce the bleeding and improve resolution, windowing of the source data is used.



Go to the top of the page
+Quote Post

Posts in this topic

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 28th November 2015 - 18:17