| Author |
Message |
magnetra
Joined: 21 Apr 2005
Posts: 260
Helped: 3
Location: 27.45N, 85.20E KTM, NP
|
 12 May 2006 16:36 Signalling rate and Bandwidth |
|
|
|
|
"The Nyquist bandwidth required for signalling rate of R is R/2." I think this relation is meant only forpolar PAM signalling. Does the same relation between bandwidth and signalling rate hold for other signalling methods (unipolar, bipolar, manchester)?
M
|
|
| Back to top |
|
 |
flatulent
Joined: 19 Jul 2002
Posts: 4877
Helped: 294
Location: Middle Earth
|
| 12 May 2006 19:08 Re: Signalling rate and Bandwidth |
|
|
|
|
| This is the minimum sampling rate to be able to reconstruct the signal without error. It has nothing to do with modulation methods.
|
|
| Back to top |
|
|
SkyHigh
Joined: 13 Jan 2005
Posts: 376
Helped: 51
|
| 12 May 2006 19:35 Re: Signalling rate and Bandwidth |
|
|
|
|
| Manchester Coding is a Coding method. It has nothing to do with modulation, but the signalling rate used is twice that of the data source's signalling rate.
|
|
| Back to top |
|
|
magnetra
Joined: 21 Apr 2005
Posts: 260
Helped: 3
Location: 27.45N, 85.20E KTM, NP
|
| 13 May 2006 18:09 Re: Signalling rate and Bandwidth |
|
|
|
|
My question was regarding the relation between Nyquist BW and signaling rate as defined the ideal solution to Nyquist Pluse Shaping Criteria.
The Nyquist BW so defined is the minimum tx bw for zero ISI and is equal to one half of the bit rate (1/Tb). This relation between Nyquist BW and bit rate, does it hold for unipolar, polar, bipolar signaling equally?
From earlier replies, I thought my question might have been misunderstood. HOpe this is clear. Or if I'm wrong please correct me and please explain me the missing link in my understanding regards to this topic, if any?
Regards
M
|
|
| Back to top |
|
|
magnetra
Joined: 21 Apr 2005
Posts: 260
Helped: 3
Location: 27.45N, 85.20E KTM, NP
|
| 15 May 2006 17:42 Signalling rate and Bandwidth |
|
|
|
|
| flatulent and anyone viewing this post, please give some comments.....is my query trival?
|
|
| Back to top |
|
|
flatulent
Joined: 19 Jul 2002
Posts: 4877
Helped: 294
Location: Middle Earth
|
| 15 May 2006 19:08 Re: Signalling rate and Bandwidth |
|
|
|
|
The Nyquist filtering criteria is a linear phase response and a symmetrical magnitude response around the half voltage point. This produces sinc type output pulses but the zero crossings are at the peaks of adjacent pulses.
This is for half of the symbol rate independent of the amplitude level, number of levels, and DC offset.
|
|
| Back to top |
|
|
sidra
Joined: 05 Apr 2006
Posts: 107
Helped: 12
Location: see in yr heart...found it?
|
| 17 May 2006 7:31 Re: Signalling rate and Bandwidth |
|
|
|
|
| hi...sid here...this is a universal law...it is nothing to do with the technique u are using...u can reconstruct yr original signal by applying a proper filter after using this law...sidra_maheen84(at)yahoo.com
|
|
| Back to top |
|
|
