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How to add phase noise (in dBc) at a certain freq. offset - RF Cafe
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| shilpika
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Post subject: How to add phase noise (in dBc) at a certain freq. offset
Posted: Wed Oct 28, 2009 6:18 am
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Joined: Wed Oct 28, 2009
6:10 am
Posts: 1 |
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Hi,
I have the following data
| Offset
From Carrier | Phase Noise |
-------------------------------------------------------
| 1 kHz | -84 dBc/Hz |
| 10 kHz | -100 dBc/Hz
|
| 100 kHz | -96 dBc/Hz |
| 1 MHz | -109
dBc/Hz |
| 10 MHz | -122 dBc/Hz |
I
have a data of lengh L in time domain.
How do
I use the above information on Phase noise and add
to my signal ???
Thanks
Shilpika
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nubbage |
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Post subject: Re: How to add phase noise (in dBc) at a certain freq.
offset
Posted: Thu Nov 05, 2009 4:05 am
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| General |
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Joined: Fri Feb 17, 2006
12:07 pm
Posts: 304
Location: London UK
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Hi shilpika
you need to transform from the time
domain to the frequency spectrum domain. I think
I am right in saying that the data length L in the
time domain is not relevant.
What is relevant
is the date rate and the modulation method. Thus
a data rate of 8 megabits per second passed through
a 64QAM modulator has a certain symbol rate and
this relates to the spectrum width around the carrier
frequency center. Armed with that knowledge and
the level of the carrier, you can estimate the noise.
Draw a spectrum distribution curve from the data
you have of offset frequency and noise, and superimpose
a Gaussian curve for the signal spectrum. That will
show the relative noise and carrier levels.
_________________
At bottom, life is all
about
Sucking in and blowing out.
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Posted 11/12/2012
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