Kitz Forum
Broadband Related => Broadband Technology => Topic started by: Weaver on August 24, 2020, 02:20:12 PM
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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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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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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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:thumbs: Thank you. That is what I could not fully recall. Team work prevails, once again. :)
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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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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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That is what I have read too. Indeed, an interesting point. Approximately double the power.