Talk:Symbol rate

message: The "Baud rate" article was renamed to "Baud" in 24 January 2007, but "Baud rate" is still forwarded to "Baud".
Merge suggestion templates were placed in May/June 2007 on the Modulation rate, Symbol (data) and Baud articles.
Merge suggestion templates were placed in December 2007 on the Significant condition and Symbol (data) articles.
Yesterday I merged the "modulation rate" and "Symbol rate" articles into the "baud rate/Baud" article, since there has not been any protests to the merge suggestion templates. However, the forwarding of the Symbol rate article was reverted. To resolve the dispute, I suppose we need to vote. Mange01 (talk) 08:34, 6 May 2008 (UTC)
thread_title: History 

message: Should Symbol rate be merged with Baud, which already is merged with Baud rate and Modulation rate? And what should the name be of the article?
*Strongly support. The main article title may either be Symbol rate or Baud. Argument: These rates are synonyms. Mange01 (talk) 08:34, 6 May 2008 (UTC)
replies: text: Agree with the tone of the previous comment. ("First, I also undid the merge of [[Modulation rate]") Laguna CA (talk) 05:26, 20 April 2011 (UTC)
thread_title:  Survey 1: Merge with Baud? Article name? 

message: Should Symbol rate be merged with Symbol (data)?
*Support. The articles discuss the same issues, and one of them is reduntant. I can not think of any issue that should be discussed in one of the articles but not the other. Mange01 (talk) 08:34, 6 May 2008 (UTC)
thread_title:  Survey 2: Merge with Symbol? 

message: If the answer is "no" on survey 1, I suppose Baud rate should point at Symbol rate instead of the Baud article for the same reason? 
For now the "Symbol rate" article is not very well written, and I don't understand what difference you had in mind. I have already merged text from "Symbol rate" and "Modulation rate" into the "Baud rate" article. Can we copy all the text from the current Baud article to the Symbol rate article? After that, perhaps some text may be removed from the Baud unit article? At least temporarily while waiting for the survey result, in view to clarify how two separate articles would look like? As a third step, I suggest that the Symbol (data) text is merged into the Symbol rate article.
I agree that the term Baud rate is problematic. Not so much because it has been confused with bit rate, it was long time since I saw that. I teach using a course literature that claims that 1 baud = 1 symbol, which is an understandable mistake, since "rate" in "baud rate" can be understood as "per time unit". But, as you pointed out, we have to mention baud rate in the articles since it is a widespread term.
There are some units that are forwarded to the measure article. Example: (bit/s)/Hz -> Spectral efficiency. Is it important to always create separate unit articles? Why?
(You and I Graham had a discussion a few days ago, but then you gave me the impression that you supported all the suggested merges. Sorry for misunderstanding you.) 
Mange01 (talk) 22:09, 6 May 2008 (UTC)
replies: text: Discussion: I theoretically agree with the idea, but "symbol" does not have a definite number of bits. As such, "Symbol rate" is meaningless. Example: If the a symbol rate of 2 with the symbols "0" and "1" is equivalent to a symbol rate of 1 with the symbols "0", "1", "2" and "3" is equivalent to a symbol rate of 1 with the symbols "00", "01", "10" and "11"; how does symbol rate have anything other than a wishy-washy, theoretical meaning? I totally agree that "symbol rate" has a place in theoretic discussions of communications, but until some hard definition is placed on "symbol", symbol can be redefined to be any bit rate one desires: as such, "Symbol Rate", while definitely a useful term for theoretical communications discussions, has no concrete meaning. Thus, "symbol" and especially "symbol rate" (which is doubly vague) should be treated as the theoretical construct they are. Even if X=8 commonly, X and 8 are vastly different terms. Laguna CA (talk) 05:40, 20 April 2011 (UTC)
replies: text: Symbol rate is a well-defined concept used in data communication literature, and that also is of practical use in modem specifications. See my answer below. I think the article needs illustrations that explain things better, for example a time diagram showing the signal from an 8QAM modulator or a 4PSK modulator. An analogy: You could say that modems play music to each other - they represent bits by tones. The symbol rate is the number of tones that are played per second. An 8 QAM modem is like a music instrument with 8 keys, each generating a tone with different amplitude and phase. Each key represents 3 bits. So, if the musician (the modem) plays 100 tones per second (or symbols per second) the data rate is 300 bit/s. Mange01 (talk) 06:52, 20 April 2011 (UTC)
thread_title:  Discussion continued 

message: I'm sorry that we appear to have different approaches to improving this area of Wikipedia, but it's good that we both want to do it.  I am not, like you, a "wikiholic", so it would be unfair of me to stand in your way if you want to push changes through.  I will reposition myself as a helper.  I have a long history of work with both passband and baseband communication systems, I have designed symbol constellations, channel equalizers, etc., so I think I understand many of the issues at a deep level.  I will make a couple of points and try to explain my position fully and then I will let you take the lead.  I don't know how long we should wait to see if anyone else contributes to this discussion.  I have the impression I showed up at the eleventh hour myself.
The parallel of (bit/s)/Hz redirecting to Spectral efficiency is not appropriate here because (bit/s)/Hz is a combination of fundamental quantities and units of measure.  By contrast, baud is a single word assigned as the unit of measure of symbol rate to honor a major contributor to the field.  It deserves its own page to explain the derivation from Emile Baudot's name and to link to that article.  Please also consider that the (mis)use of the term needs to be explained and this should not be done in an article about symbols.
If we agree that articles are not well written, we should consider a gradual re-write as an alternative to copying existing text from one place to another.  This would be facilitated by having in mind where we want this set of articles to end up.  I will now explain where I think that should be and leave the final structure to you.
The Symbol (data) article is the most fundamental, should be the longest and most thorough.  It should make free, but only correct, use of the other terms.
The Symbol rate article should be very brief and point the reader to Symbol (data).  However, there should be hooks here for related articles.  Modulation rate should redirect to this article and the equivalence of these terms should be stated clearly in the Symbol rate article.  It should also be stated that baud is the unit of measure of symbol rate, thus referencing that article.  The non-equivalence of baud rate should be noted, thus referencing that article as well.  Whether someone is looking for the correct or incorrect use of terms, when they reach this article they should know where to go next.
The baud article should also be very brief and point the reader to symbol rate.  This is where Emile Baudot gets a mention.  Again, it should be pointed out that baud rate is used in contexts unrelated to symbols, allowing a reader to click over to that article.
The baud rate article needs sections on each possible misuse of the term.  As I see it, these are 1) the same as baud, with "rate" erroneously appended, 2) the use where bit rate would be the correct term and 3) the use to mean gross bit rate, as distinct from payload bit rate, where communication involves a protocol overhead.
That makes one large, one medium/short and two very brief articles with modulation rate redirected as at present.
--GrahamDavies (talk) 14:25, 7 May 2008 (UTC)
replies: text: Discussion: I theoretically agree with the idea, but "symbol" does not have a definite number of bits. As such, "Symbol rate" is meaningless. Example: If the a symbol rate of 2 with the symbols "0" and "1" is equivalent to a symbol rate of 1 with the symbols "0", "1", "2" and "3" is equivalent to a symbol rate of 1 with the symbols "00", "01", "10" and "11"; how does symbol rate have anything other than a wishy-washy, theoretical meaning? I totally agree that "symbol rate" has a place in theoretic discussions of communications, but until some hard definition is placed on "symbol", symbol can be redefined to be any bit rate one desires: as such, "Symbol Rate", while definitely a useful term for theoretical communications discussions, has no concrete meaning. Thus, "symbol" and especially "symbol rate" (which is doubly vague) should be treated as the theoretical construct they are. Even if X=8 commonly, X and 8 are vastly different terms. Laguna CA (talk) 05:40, 20 April 2011 (UTC)
replies: text: Symbol rate is a well-defined concept used in data communication literature, and that also is of practical use in modem specifications. See my answer below. I think the article needs illustrations that explain things better, for example a time diagram showing the signal from an 8QAM modulator or a 4PSK modulator. An analogy: You could say that modems play music to each other - they represent bits by tones. The symbol rate is the number of tones that are played per second. An 8 QAM modem is like a music instrument with 8 keys, each generating a tone with different amplitude and phase. Each key represents 3 bits. So, if the musician (the modem) plays 100 tones per second (or symbols per second) the data rate is 300 bit/s. Mange01 (talk) 06:52, 20 April 2011 (UTC)
thread_title:  Reply to the above discussion 

message: In this article and in the article for "baud", the term "symbol" may be a better term to use the the term "bit" only if the term "symbol" has more general usage that its use in telecom.  IEEE usage, for example, interchangeably refers to "Baud" and to "bit rate".  If "Baud" is used outside of telecom (outside of electronics, actually) then "symbol rate" might be a better definition than "bit rate".  However, it is possible too that use of the term "symbol" is due to an error in translation.  
As examples, consider that "symbol" can appropriately refer to certain ASCII characters.  The binary form of these symbols requires 7 bits or more (depending on the character set).   The metric (aka the parameter) used to compare different devices and connections that represents the speed at which data travels is "bit rate" or "baud", not "symbol rate".  Because "baud" refers to rate by definition it is not expressed as "baud rate". 
Incorrect usage was not unusual in the previous century.  This century it almost never heard because the rate is typically in units of millions (Mega-) or billions (Giga-).
Kernel.package (talk) 01:46, 14 July 2010 (UTC)
replies: text: I changed the article now to further clarify that in this context a symbol is a waveform, e.g. a pulse or a modulated sinewave. It has nothing to do with characters. In today's modems and Ethernet transmision, the bit rates are much higher than the symbol rates. For example a telephone modem may have a symbol rate of 2400 baud upstreams and 8000 baud downstreams, while the bit rate is 48000 and 56000 bit/s respectively. So it is important to not confuse bit rate with baud.  In old modems there were only two symbols, one representing 0 and one representing 1, meaning that the symbol rate and gross bit rate were the same. Also on most serial interfaces (EIA232 and similar), there are only two voltage levels of the pulses, meaning that gross bit rate and baud is the same in that context. But in all modern modems (faster than 2400 bit/s) and high-speed Ethernet (100 Mbps over copper or faster), there are more than two alternative symbols, meaning that the Ethernet pulses have more than two levels, or the modem sinewaves have more than two phases and amplitudes. This implies that each symbol represents more than one bit. IEEE people would never confuse the concepts. The bit rate article also expains this. Maybe someone can provide an illustration that further clarifies this common misunderstanding. Mange01 (talk) 08:32, 14 July 2010 (UTC)
thread_title:  Baud, bits and symbol