How to define SNR in unit of dB?

Hey, all
I am not expert in DSP field, and just came cross
some signal processing papers for my research purpose.

In these papers, the word "dB" is often appearing
for representing the signal-to-noise ratio.

So I want to know how to define SNR
in the unit of dB?

Thanks for your points.

Fred

On Thu, 8 Jan 2004 00:30:26 -0600, "Fred" <f0z6305@labs.tamu.edu>
wrote:

>Hey, all
>I am not expert in DSP field, and just came cross
>some signal processing papers for my research purpose.
>
>In these papers, the word "dB" is often appearing
>for representing the signal-to-noise ratio.
>
>So I want to know how to define SNR
>in the unit of dB?
>
>Thanks for your points.


10 log10 (Signal power / Noise power)


You might like to try to get a copy of IEC60027-3

Regards,
Allan.

Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in message news:<5e1qvvcdj3v0if99b5tf35rfjgl6umhbor@4ax.com>...

> You might like to try to get a copy of IEC60027-3

...which is what published by whom?

Rune

Fred,

Just find 10*log( (signal power)/(noise power) ) where the log is a Brigg's
log (base 10)

Clay




"Fred" <f0z6305@labs.tamu.edu> wrote in message
news:bbidnUpEUpiMZGGiRVn-hg@comcast.com...
> Hey, all
> I am not expert in DSP field, and just came cross
> some signal processing papers for my research purpose.
>
> In these papers, the word "dB" is often appearing
> for representing the signal-to-noise ratio.
>
> So I want to know how to define SNR
> in the unit of dB?
>
> Thanks for your points.
>
> Fred
>
>

"Clay S. Turner" wrote:

> Fred,
>
> Just find 10*log( (signal power)/(noise power) ) where the log is a Brigg's
> log (base 10)
>
> Clay
>
> "Fred" <f0z6305@labs.tamu.edu> wrote in message
> news:bbidnUpEUpiMZGGiRVn-hg@comcast.com...
> > Hey, all
> > I am not expert in DSP field, and just came cross
> > some signal processing papers for my research purpose.
> >
> > In these papers, the word "dB" is often appearing
> > for representing the signal-to-noise ratio.
> >
> > So I want to know how to define SNR
> > in the unit of dB?
> >
> > Thanks for your points.
> >
> > Fred
> >
> >

You can substitute variance for power (average power) assuming there is no dc
in the signal or noise.

Tom

Clay S. Turner wrote:
> Fred,
> 
> Just find 10*log( (signal power)/(noise power) ) where the log is a Brigg's
> log (base 10)

Clay,

I don't believe I've ever heard it called "Brigg's log" before. Where did you
get that?
-- 
%  Randy Yates                  % "...the answer lies within your soul
%% Fuquay-Varina, NC            %       'cause no one knows which side
%%% 919-577-9882                %                   the coin will fall."
%%%% <yates@ieee.org>           %  'Big Wheels', *Out of the Blue*, ELO
http://home.earthlink.net/~yatescr

On 8 Jan 2004 06:30:55 -0800, allnor@tele.ntnu.no (Rune Allnor) wrote:

>Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in message news:<5e1qvvcdj3v0if99b5tf35rfjgl6umhbor@4ax.com>...
>
>> You might like to try to get a copy of IEC60027-3
>
>...which is what published by whom?

IEC = International Electrotechnical Commission.  Most standards
bodies (e.g. ANSI) will be able to provide it.

The document title is
"IEC 60027-3 Ed. 3.0 b:2002   	   Letter symbols to be used in
electrical technology - Part 3: Logarithmic and related quantities,
and their units"

Regards,
Allan.

Hello Randy,

Briggs constructed some of the earliest log tables and he was the one who
suggested using base 10.

Check out:

http://www.thocp.net/biographies/briggs_henry.html

Clay

p.s. A math book that I got as a kid covered both Briggs and Napier logs. I
still have the book. The book is "Technology Mathematics Handbook" by Jan
Tuma




"Randy Yates" <yates@ieee.org> wrote in message
news:7wnLb.33815$IM3.15849@newsread3.news.atl.earthlink.net...
> Clay S. Turner wrote:
> > Fred,
> >
> > Just find 10*log( (signal power)/(noise power) ) where the log is a
Brigg's
> > log (base 10)
>
> Clay,
>
> I don't believe I've ever heard it called "Brigg's log" before. Where did
you
> get that?
> -- 
> %  Randy Yates                  % "...the answer lies within your soul
> %% Fuquay-Varina, NC            %       'cause no one knows which side
> %%% 919-577-9882                %                   the coin will fall."
> %%%% <yates@ieee.org>           %  'Big Wheels', *Out of the Blue*, ELO
> http://home.earthlink.net/~yatescr

allnor@tele.ntnu.no (Rune Allnor) wrote in message news:<f56893ae.0401080630.532c8fe0@posting.google.com>...
> Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in message news:<5e1qvvcdj3v0if99b5tf35rfjgl6umhbor@4ax.com>...
> 
> > You might like to try to get a copy of IEC60027-3
> 
> ...which is what published by whom?
> 
> Rune

IEC 60027-3, Letter symbols to be used in electrical 
technology &#8212; Part 3: Logarithmic quantities and units.

https://domino.iec.ch/webstore/webstore.nsf/artnum/028981

Ken

Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in message news:<932svvojvpohp5qk04olrt2ojn6lpjs46r@4ax.com>...
> On 8 Jan 2004 06:30:55 -0800, allnor@tele.ntnu.no (Rune Allnor) wrote:
> 
> >Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in message news:<5e1qvvcdj3v0if99b5tf35rfjgl6umhbor@4ax.com>...
> >
> >> You might like to try to get a copy of IEC60027-3
> >
> >...which is what published by whom?
> 
> IEC = International Electrotechnical Commission.  Most standards
> bodies (e.g. ANSI) will be able to provide it.
> 
> The document title is
> "IEC 60027-3 Ed. 3.0 b:2002   	   Letter symbols to be used in
> electrical technology - Part 3: Logarithmic and related quantities,
> and their units"
> 
> Regards,
> Allan.

Thanks.

Rune