# Question about root\_raised\_cosine

**URL:** <https://www.ruby-forum.com/t/question-about-root-raised-cosine/231579>\
**Category:** GNU Radio\
**Created:** [August 16, 2014, 6:42pm UTC](https://www.ruby-forum.com/t/question-about-root-raised-cosine/231579 "2014-08-16T18:42:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [August 16, 2014, 6:42pm UTC](https://www.ruby-forum.com/t/question-about-root-raised-cosine/231579/1 "2014-08-16T18:42:58Z")

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I use a variable to create the taps for arbitrary polyphase resampler  
block, and for that the variable that I call “taps1” I give the  
following value firdes.root\_raised\_cosine(gain, sampling\_freq,  
symbol\_rate, alpha, ntaps), which is raised cosine filter creates. But  
I’m not sure how and what parameters to use. I try to put parameters  
whose meanings are as described above but the result is not as expected.

Does anyone know how to use firdes.root\_raised\_cosine(,) and  
parameters are suitable for this?

Thank you

Andrés Gómez

Electronic engineering student