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Kitz Forum
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Bits per bin and SNRM difference
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Topic: Bits per bin and SNRM difference (Read 852 times)
Weaver
Senior Kitizen
Posts: 11459
Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Bits per bin and SNRM difference
«
on:
August 24, 2020, 02:20:12 PM »
Question: In DSL, if you improve the SNR on a tone by
x
dB so as to get a 1 bit increase in bit-loading, what is
x
?
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burakkucat
Respected
Senior Kitizen
Posts: 38300
Over the Rainbow Bridge
Re: Bits per bin and SNRM difference
«
Reply #1 on:
August 24, 2020, 04:15:16 PM »
I presume that you are asking about the absolute SNR and not the SNRM for a particular frequency?
It's a good question and I feel there must be some "rule of thumb" (or paw) which would allow an estimate to be made.
I suspect that either ejs or Kitz may be able to assist . . .
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100% Linux and, previously, Unix. Co-founder of the
ELRepo Project
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digbey
Member
Posts: 59
Re: Bits per bin and SNRM difference
«
Reply #2 on:
August 24, 2020, 04:56:02 PM »
https://kitz.co.uk/adsl/adsl_technology.htm
~
Bit Loading
If the signal is good then 15 bits (maximum) can be allocated to that tone.
Each 3dB of SNR equates to 1 bit (of data),
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burakkucat
Respected
Senior Kitizen
Posts: 38300
Over the Rainbow Bridge
Re: Bits per bin and SNRM difference
«
Reply #3 on:
August 24, 2020, 05:36:43 PM »
Thank you. That is what I could not fully recall. Team work prevails, once again.
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100% Linux and, previously, Unix. Co-founder of the
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Please consider making a
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Weaver
Senior Kitizen
Posts: 11459
Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Bits per bin and SNRM difference
«
Reply #4 on:
August 24, 2020, 08:29:03 PM »
Thanks! Measurements taken from SNR and bits-per-bin graphs suggested 3dB to me, but I wanted another opinion. Thanks to Kitz also.
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4candles
Kitizen
Posts: 3298
Not young enough to know everything
Re: Bits per bin and SNRM difference
«
Reply #5 on:
August 24, 2020, 10:52:41 PM »
Interesting parallel - that 3db is generally accepted as the smallest difference in level that is easily heard by most people listening to speech or music.
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To err is human - to purr feline
Zen FTTC 40/10 + Digital Voice FRITZ!Box 7530
Weaver
Senior Kitizen
Posts: 11459
Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Bits per bin and SNRM difference
«
Reply #6 on:
August 24, 2020, 11:49:45 PM »
That is what I have read too. Indeed, an interesting point. Approximately double the power.
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Bits per bin and SNRM difference