Talk:Intersymbol interference

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[edit] GMSK wants ISI

Some techniques try to reduce the amount of interference between consecutive symbols, such as Gaussian minimum shift keying and certain other phase-shift keying variants

as far as I know, the GMSK does not try to reduce the ISI between the symbols, but actually introduces it bgy a gaussian filter so that it will be possible to recover lost symbols according to the others using Viterbi algorithm... Can you report the source of this information?? Alessio Damato 17:02, 30 November 2005 (UTC)

[edit] ...

"ISI is introduced before sending by using a gaussian filter"

Do you mean prevented before instead of introduced? We do not want ISI, we want to remove it. —Preceding unsigned comment added by 192.91.60.11 (talk • contribs)

On the whole, yes, it is undesired. However some systems (eg duobinary signalling) do introduce controlled ISI. Not sure offhand about GMSK, but will look into it. Either way, as part of the revamp of the article I am doing I will add details about this in. Blair - Speak to me 09:10, 10 December 2007 (UTC)

[edit] ...

I have removed the following misplaced text from the end of the External Links section (reproduced here verbatim): "Intersymbol Interference and Equalization The all-pass assumptionmade in the AWGN (or non-dispersive) channel model is rarely practical. Due to the scarcity of the frequency spectrum, we usually filter the transmitted signal to limit its bandwidth so that efficient sharing of the frequency resource can be achieved. Moreover, many practical channels are bandpass and, in fact, they often respond differently to inputs with different frequency components, i.e., they are dispersive. We have to refine the simple AWGN (or non-dispersive) model to accurately represent this type of practical channels. One such commonly employed refinement is the dispersive" Idunno271828 (talk) 02:02, 21 April 2008 (UTC)