Talk:Minimum-shift keying

message: How MSK is placed ?
:What does your question mean?? Oli Filth 11:59, 22 September 2006 (UTC)
thread_title: Question

message: MSK is a special case of CPM, but not necessarily have to be merged. I disagree on merging. Memming 16:17, 2 May 2007 (UTC)
thread_title: Merging to CPM

message: In the section "Gaussian minimum-shift keying", the term "modulation memory" is used and is linked to http://en.wikipedia.org/wiki/Modulation_memory whose target is actually http://en.wikipedia.org/wiki/Modulation_memory#Digital_modulation_methods.  The target page does not define or even use the term "modulation memory".  I lack the technical knowledge to remedy this.  I hesitate to simply remove the link, since I would like someone with the necessary knowledge to edit the target page (or create a new one) to define the term.
Dhikr (talk) 14:28, 23 September 2012 (UTC)
thread_title:  Modulation memory? 

message: Yesterday, I inserted Bluetooth Low Energy into the list of notable GMSK examples as "in a close approximation [of GMSK]". I used the phrase "close approximation" because the BLE standard only requires that the modulation index be close to 0.5, not exactly 0.5. User Glrx reverted this stating that "approx should not be most notable".
Frankly, I think that my edit was entirely reasonable based on, for example, this article:
http://www.digikey.com/us/en/techzone/wireless/resources/articles/bluetooth-goes-ultra-low-power.html
"Finally, Bluetooth Low Energy’s modulation scheme also contributes to its low energy profile as well as greater robustness. Both Classic Bluetooth and Bluetooth Low Energy utilize Gaussian frequency shift keying (GFSK). However, Classic Bluetooth uses a modulation index of 0.35, while the modulation index for Bluetooth Low Energy is set at between 0.45 and 0.55, which is close to the level for Gaussian minimum shift keying (GMSK)."
If, after a reasonable time, no one other than Glrx objects, I'm going to re-instate this edit. We could use at least one more example of GMSK in the real world and Bluetooth Low Energy is probably the most-common example after GSM.
Atlant (talk) 20:12, 3 September 2013 (UTC)
thread_title:  Bluetooth LE as an example of GMSK 

message: I am concerned by the statement that the modulation index is 0.25.  My understanding is that it has a modulation index of 0.5.  The best online description of MSK that that I have found so far is http://www.winlab.rutgers.edu/~narayan/Course/WSID/Lectures02/lect11.pdf.  J.G Proakis in “Digital Communications” also states that the index is 0.5.
I think that the problem lies in the use of the definition of modulation index for analogue FM.  For 2FSK it is the difference in the upper and lower frequencies divided by the symbol rate (see http://www.cdt21.com/resources/Modulation/modulation_FSK.asp).
Sweng1158 (talk) 08:02, 2 November 2013 (UTC)
thread_title:  Modulation Index 

message: It might be worth noting that the so-called complexity of GMSK ISI is not really an issue in many receiver implementations, since the successive symbols are always in relative quadrature phase, and so the ISI is always 90 degrees out of phase with the symbol it is interfering with.
--DavidABurgess (talk) 17:45, 26 November 2018 (UTC)
thread_title:  GMSK ISI a non-issue in clever receiver designs 

message: The Marcum-Q-function seems to be misplaced in this context should be replaced with the usual one, Q-function.
2001:4C80:50:42:155B:EF67:91F8:4D4D (talk) 13:51, 18 December 2019 (UTC)
replies: text: Done. cathartid - talk 05:58, 26 April 2020 (UTC)
thread_title:  Wrong Q-function