Signal filtering

2011 10 20
2 个回答
回答已采纳
9 次查看（30 天）

0 个投票

Hi :) I'd like to know how to divide a signal into frames (for example 25 ms frames) without overlapping. And how do I multiply each frame using the Hamming window?
Thanks!

请先登录，再回答此问题。

 采纳的回答

Wayne King
Wayne King 2011-12-2

0 个投票

Hi Anna, If you're using reshape you can't change the number of elements. so
x = randn(10,1);
x1 = reshape(x,5,2);
is ok, but
x1 = reshape(x,6,2);
is not.
Yes, you can use buffer to overlap your signal segments.
Note that buffer() will prepend and append zeros as necessary:
x = 1:10;
x1 = buffer(x,5,2);

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Anna
Anna 2011-12-2
It wooooooooooooooorks. Thank youuuuu. You're so awesome! :D

请先登录，再进行评论。

更多回答（1 个）

Wayne King
Wayne King 2011-10-20

0 个投票

You have to know your sampling rate in order to know how many samples a 25-ms frame is. Here I'll assume it's 10 kHz. So 250 samples is 25 msec and there are 40 such segments in 1 second.
x = randn(1e4,1);
x = reshape(x,250,40);
ham = repmat(hamming(250),1,40);
x = x.*ham;
Each column of x is a 25 msec segment multiplied by a Hamming window.

2 个评论
显示 无 隐藏 无

Jan
Jan 2011-10-20
I expect that "x = bsxfun(@times, x, hamming(250));" is faster than creating ham explicitely.
Anna
Anna 2011-12-2
How come when I try to add in an audio signal (using wavread) and I try to reshape it, (I used 16kHz for Fs), an 'Error' shows up. It says that it should have the same number of elements.
And is it also possible to use buffer in the circumstance that I need to overlap?
Thank You!

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Hamming 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by