Talk:Raised-cosine filter

From Wikipedia, the free encyclopedia
Jump to: navigation, search
          This article is of interest to the following WikiProjects:
WikiProject Electronics  
WikiProject icon This article is part of WikiProject Electronics, an attempt to provide a standard approach to writing articles about electronics on Wikipedia. If you would like to participate, you can choose to edit the article attached to this page, or visit the project page, where you can join the project and see a list of open tasks. Leave messages at the project talk page
 ???  This article has not yet received a rating on the project's quality scale.
 ???  This article has not yet received a rating on the project's importance scale.
 
WikiProject Telecommunications  
WikiProject icon This article is within the scope of WikiProject Telecommunications, a collaborative effort to improve the coverage of Telecommunications on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
 ???  This article has not yet received a rating on the quality scale.
 ???  This article has not yet received a rating on the importance scale.
 

Analogue or digital[edit]

PAR said on Oli Filth's talk page:

"The raised cosine filter is listed on the linear analog filter template, but it is a linear DIGITAL filter. This should be fixed. PAR 21:29, 25 August 2006 (UTC)"

I wasn't even aware that the "analog filter" template had been added, but according to the history, you added it!!
Don't change the subject! My bungled edits are not the subject of this discussion! Please put all such discussions on the Wikipedia page [[Bungled edits of PAR]] unless that page has been deleted for excessive length. PAR 22:56, 25 August 2006 (UTC)
As to whether raised-cosine is analogue or digital, it's an interesting question. Technically, "raised-cosine filter" as presented in this article is just a mathematical expression that operates in continuous-time, continuous-frequency; this would imply an analogue implementation. However, it happens to be implemented digitally in pretty much all applications. However, the digital implementation requires discrete-time equations. So it's probably best to not call it either. Oli Filth 22:12, 25 August 2006 (UTC)
Perhaps a template for linear digital filters? PAR 22:56, 25 August 2006 (UTC)
Perhaps, however there's currently nothing in the raised-cosine article that even hints at the digital implementation - the equations would be different, as they'd be discrete-time (obviously).
Actually, I'm not sure what specific types of digital filters there are. Because the designer has so much more flexibility in their design than in the analogue domain, generally digital filters are custom-designed according to requirements, using the Parks-McLellan algorithm, etc., or designed and then multiplied by an appropriate window. I'm not sure how many specific digital filters there out there with names. Oli Filth 23:04, 25 August 2006 (UTC)
It's mathematically defined as a linear analog filter that would ideally be used to convert a digital dirac-pulse signal to an analog continuous-time signal. Typically root-raised-cosine filters are used, however, as stated in the article. Strstrep (talk) 17:47, 2 April 2008 (UTC)

Alpha or beta?[edit]

It seems that the roll-off parameter is more commonly known as alpha. Temblast (talk) 11:29, 24 June 2011 (UTC)

The Raised-cosine-impulse.svg picture has label bugs on the time axis.[edit]

The bug can be found in the python code:

ax.set_xticks([-3,-2,-1,0,3,2,1])

ax.set_xticklabels(["-3T","-2T","-T","0","T","2T","3T"])


It should probably be:

ax.set_xticks([-3,-2,-1,0,1,2,3])

ax.set_xticklabels(["-3T","-2T","-T","0","T","2T","3T"]) — Preceding unsigned comment added by 81.230.178.57 (talk) 10:44, 12 August 2011 (UTC)

Corrected. Thanx. --ElectroKid (talkcontribs) 22:00, 28 August 2011 (UTC)