Talk:Frequency-shift keying

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
WikiProject Telecommunications (Rated Start-class)
WikiProject iconThis article is within the scope of WikiProject Telecommunications, a collaborative effort to improve the coverage of Telecommunications on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 ???  This article has not yet received a rating on the project's importance scale.
 
WikiProject Amateur radio (Rated Start-class, Mid-importance)
WikiProject iconThis article is within the scope of WikiProject Amateur radio, which collaborates on articles related to amateur radio technology, organizations, and activities. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 

Can someone with knowledge of DFSK add information on that to this page? —Preceding unsigned comment added by 128.253.139.181 (talk) 01:28, 1 April 2010 (UTC)

FFSK?[edit]

oh A type of FSK that I have used for signalling in the past consists of a '1' being represented by a single cycle of a frequency f, and a '0' by 1.5 cycles of frequency f + f/2, phase continuous (typical frequencies would be 1200Hz and 1800Hz). It's a very neat and compact scheme, very easy to synthesise, with every bit period being equal, and very easy to decode, counting zero-crossings. I always though this was called FFSK, with the extra F standing for 'Fast', but currently there is no article about this. Is it perhaps known by another name? Graham 11:46, 8 February 2006 (UTC)

Yes. FFSK is equivalent to MSK. Oli Filth 14:57, 21 August 2006 (UTC)
No. FFSK is equivalent to what the fine article calls "Audio FSK" Ok, to be fair, there is a problem here that the same term is used to mean different things. but could we try to make this more clear in tfa? (sorry at the moment i have no clear idea how). — Preceding unsigned comment added by 194.209.214.225 (talk) 13:56, 18 August 2011 (UTC)

ASK gets all the love :([edit]

I'd like to see this article brought up to the quality of Amplitude-shift_keying. I'm not an EE, but I do have Stallings open here, but the amount of actual detail is pretty thin. I don't have the background to elaborate or generate the math or diagrams necessary. ==

MSK[edit]

I think the article is wrong about the bit rate to frequency shift ratio. The difference between the higher and lower frequency (i.e., twice the frequency shift) is equal to half the bit rate.

The formula for the frequency shift is

where is the bit rate, is the frequency shift and the modulation index for MSK. Hence, the difference between the higher and lower frequency is

--Drizzd 13:13, 9 July 2006 (UTC)


Indeed. I've altered this. Oli Filth 14:52, 21 August 2006 (UTC)

Implementation Example - moved from page[edit]

Need a diagram for this to be useful in the article. I may do this myself if I have time.

The greatest single reason for the widespread use of FSK is its simple implementation. All that is required is an oscillator whose frequency can be switched between two preset frequencies. This can be easily achieved using the 555 timer IC. As the carrier signal is shifted between two preset frequencies, hence this technique of signal modulation got the name FSK.


The frequency corresponding to logic 0 and 1 are called 'space' and 'mark' frequency respectively. The FSK generator is constructed using a 555-timer in astable mode, with its frequency controlled by the state of a PNP transistor. 150Hz is the standard frequency at which data input can be transmitted.

When input is logic 1, the transistor is off. The capacitor then charges through (RA+RB) up to 2/3Vcc. Then it discharges through RB up to 1/3Vcc. This exponential charging-discharging continues as long as input is logic 1.

 Mark Frequency =  = 1070 Hz

When input is logic 0, the PNP transistor is on (saturated), connecting RC across RA. Hence frequency obtained is:

 Space frequency =  = 1270 Hz

Hence by proper selection of resistors, the mark and space frequencies can be selected. The difference between 1070 and 1270 Hz is of 200 Hz and is called 'frequency drift'.

—Preceding unsigned comment added by Ktims (talkcontribs) 05:52 24 OCT 06

No problem. Btw, which program do u use for makin ccts, or are u on bitmap too? Xcentaur 07:53, 24 October 2006 (UTC)

I normally use Eagle (program) because the free version is quite good, but it doesn't produce output that's appropriate for Wiki without some editing. You could try Dia as well, I've used it a bit and it's not very useful for circuit design but it produces nice output. And there's always [1] which is great for simple circuits. --Ktims 08:50, 24 October 2006 (UTC)

Ah. Had a lot of ccts that I wanted to add but dint know how. This helps a lot. Thanks. Xcentaur 09:28, 24 October 2006 (UTC)

Incremental frequency keying?[edit]

A description of "incremental frequency keying" has recently been added. However, a Google search reveals only 39 hits, so I'm not sure it's particularly notable or widely used. Any thoughts? Oli Filth(talk) 01:01, 7 December 2007 (UTC)

I see that Google gives 313 hits for "differential frequency shift keying". Is that notable enough?

I agree that IFK is not notable enough to give an article of its own. However, I've been told that "The particular topics and facts within an article are not each required to meet the standards of the notability guidelines." -- WP:NNC. --75.19.73.101 (talk) 06:48, 13 December 2007 (UTC)

acoustic fsk[edit]

Is not yodeling a form of fsk? SyntheticET (talk) 04:00, 14 August 2008 (UTC)

Continuous Phase Frequency-Shift Keying[edit]

As both FSK and Continuous-phase frequency-shift keying (CPFSK) are a special form of frequency modulation, shouldn't CPFSK be mentioned in this article? What about 4-level Continuous FM (C4FM) - is this the same as CPFSK? --Dmitry (talkcontibs) 09:43, 26 March 2012 (UTC)

I agree, so I added a brief mention of CPFSK and C4FM to this article. --DavidCary (talk) 18:18, 28 January 2015 (UTC)

Added References and Moved MSK[edit]

I have added some references for modem implementations, added markers for necessary citations and moved the MSK stuff to the corresponding subpage. — Preceding unsigned comment added by 2A4Fh56OSA (talkcontribs) 19:03, 29 December 2012 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified one external link on Frequency-shift keying. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

As of February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete the "External links modified" sections if they want, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{sourcecheck}} (last update: 15 July 2018).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.


Cheers.—InternetArchiveBot (Report bug) 23:50, 7 October 2017 (UTC)

Weitbrecht Modem[edit]

Three questions: 1) What kind of FSK is used in a Weitbrecht Modem as used in the Telecommunication Devices by Deaf people, known by the abbreviation TTY or TDD? 2) When was the first FSK introduced for telephonic communication? 3) Why did no telephone company develop a device similar to Weitnrecht Modem already in the late 19th or early 20th century to enable deaf people to use telephone? 74.104.144.152 (talk) 15:45, 13 July 2019 (UTC) Hartmut Teuber, 13 July 2019, 11:40 am EST