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Another DMT Q: 180 degree phase reversals

Started by Unknown April 23, 2005
Hi all,

Ive come to another promblem with the project I'm doing on DSL. I can't seem 
to figure out if a 180 degree phase reversal (hardware inversion) will make 
the demodulation of the DMT signal impossible.

As I see it there will be a problem with phaseshifts that holds the carrier 
waveform "positive" for more than a half period, like the QAM modulation on 
the picture.

http://www.brantacan.co.uk/Qam.jpg

But how will it affect the DMT ?

Thanks in advance

--
Morten 


Morten M. J�rgensen wrote:
> Hi all, > > Ive come to another promblem with the project I'm doing on DSL. I can't seem > to figure out if a 180 degree phase reversal (hardware inversion) will make > the demodulation of the DMT signal impossible. > > As I see it there will be a problem with phaseshifts that holds the carrier > waveform "positive" for more than a half period, like the QAM modulation on > the picture. > > http://www.brantacan.co.uk/Qam.jpg > > But how will it affect the DMT ? > > Thanks in advance
Morten, I don't know what DMT is, but signal inversion shouldn't be a problem for demodulation and can't be fatal. You can also invert a sign in software. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������

Morten M. J�rgensen wrote:
> Hi all, > > Ive come to another promblem with the project I'm doing on DSL. I can't seem > to figure out if a 180 degree phase reversal (hardware inversion) will make > the demodulation of the DMT signal impossible.
I've always found the demodulation of a DMT signal impossible. If you know what I mean, shame on you. :-) Sorry, that's an in joke for some who have had a certain illicit experience. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein
>Sorry, that's an in joke for some who have had a certain > illicit experience.
Damn, why was that the first thing I thought of as well...

porterboy76@yahoo.com wrote:
>>Sorry, that's an in joke for some who have had a certain >>illicit experience. > > > Damn, why was that the first thing I thought of as well...
I'll bet _anyone_ who has had the experience would. :-) Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein