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daebarkee
Joined: 23 Feb 2008
Posts: 4
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 25 Feb 2008 6:51 [Help] conversion Es/No into SNR in HSDPA |
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Here, I found a few related threads.
For example, Eb/No --> SNR. http://www.edaboard.com/viewtopic.php?t=251475&highlight=eb
Es/No = C/N * B/fs
where
C/N is the carrier-to-noise ratio = SNR,
B is the channel bandwidth in Hertz,
fs is the symbol rate in Baud or symbols/second
In HSDPA, I found that B is 5 MHz.
channel symbol rate is 240 ksps for HS-DSCH. (for both QPSK and 16QAM)
So, I got
Es/No = SNR * 5M/240k
Es/No[dB] = SNR[dB] + 13.1876
Based on this formula,
(ref. CQI = max(0, min( 30, floorInteger(SNR[dB]/1.02 + 16.62) ) ) )
the CQI distribution in terms of Es/No
is Es/No: -2.7dB (cqi == 1) ~ 26.85[dB] (cqi == 30).
This result does not conform to the simulation result.
So, I think Es/No and SNR conversion can be wrong.
Because I'm not familiar with physical layer,
if anyone can give me any hint or comment, it would be great help to me!
Thank you very much!!!
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bulx
Joined: 07 Aug 2004
Posts: 170
Helped: 24
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| 26 Feb 2008 10:54 Re: [Help] conversion Es/No into SNR in HSDPA |
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Whats meant by "CQI"? Also is it that C/N known for you, and want to calculate Eb/No?
-b
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daebarkee
Joined: 23 Feb 2008
Posts: 4
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| 28 Feb 2008 13:56 Re: [Help] conversion Es/No into SNR in HSDPA |
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| bulx wrote: |
Whats meant by "CQI"? Also is it that C/N known for you, and want to calculate Eb/No?
-b |
Hello,
CQI = Channel Quality Indicator.
This splits channel state into 30 levels which support physical layer transmission in HSDPA.
C/N is just SNR. I refer to wikipedia. (http://en.wikipedia.org/wiki/Es/N0#Relation_to_Es.2FN0)
I want to know if this relation is correct in HSDPA:
Es/No = SNR * 5M/240k
Es/No[dB] = SNR[dB] + 13.1876
Thank you for your attention !!!
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fanshuo
Joined: 21 Jun 2007
Posts: 303
Helped: 5
Location: Netherlands
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| 29 Feb 2008 9:33 [Help] conversion Es/No into SNR in HSDPA |
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the relationship is correct
but pay attention that Es and Eb might not be the same
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qaqa
Joined: 05 Dec 2004
Posts: 27
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| 17 Sep 2008 21:24 Re: [Help] conversion Es/No into SNR in HSDPA |
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Es: Energy per symbol depends on your Modulation scheme.
Added after 15 seconds:
Es: Energy per symbol depends on your Modulation scheme.
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