Timeline for Number of inputs of states in Viterbi Algorithm
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| 21 hours ago | comment | added | Marcus Müller | Thanks! But you didn't get an answer, because you're not supplying the necessary information to answer it, see the comments and my answer. We can't know your channel and your signal model, nor how your modeling of the channel as FSM works out, so nobody can tell you whether your assumption is right. If the assumptions I explicitly listed are met, then you got your answer. | |
| 22 hours ago | comment | added | Ali | Learned a lot from you, Marcus! (as always) But I still haven't received a complete answer to my question. | |
| 22 hours ago | comment | added | Marcus Müller | Anyways, that's all nice discussion but doesn't contribute to the answer to your question "does it apply to me?": Still can't tell you. I explicitly listed the necessary assumption beneath my answer for you to be able to answer that yourself, based on your specific signal and channel model. Can't do that for you without knowing either! | |
| 22 hours ago | comment | added | Marcus Müller | @Ali I don't buy into marketing nonsense from defense companies. Just because some website claims they have the coolest stuff doesn't mean they have the coolest stuff. Especially, it would seem to make little sense to me to depend on a constant-envelope modulation especially in tactical radios, where ~ 30 years of cellular development have demonstrated that we can put out much more bit/s/Hz with non-constant-envelope modulations (and math also directly says that if you're restricting yourself to constant envelope, you're losing a lot of capacity) and still build portable, reliable devices. | |
| 22 hours ago | comment | added | Marcus Müller | the results of that 50 year old paper should be already in Anderson86. (the whole of chapter 5 of Anderson86 is that, in fact, and they even cite that exact paper.) | |
| 22 hours ago | comment | added | Ali | ... and the latest generation of defense tactical communications is based on CPM (even for wideband!) The waveform is called TSM from trellisware co. | |
| 22 hours ago | comment | added | Ali | OK, look at this: Schonhoff, T. A., ‘‘Symbol error probabilities for M-ary CPFSK: coherent and noncoherent detection,’’ IEEE Trans. on Comm., vol. 24, no. 6, June 1976, pp. 644–652. | |
| 22 hours ago | comment | added | Marcus Müller | I don't have [Xiong2006] in my personal library, sorry. | |
| 22 hours ago | comment | added | Ali | For BER performance, take a look at [Xiong2006] from p.314 onwards. Even CPFSK (which is definitely worse than CPM) excels PSKs. | |
| 22 hours ago | comment | added | Marcus Müller | I'll refrain from contradicting you on that; quite contrary, Fig. 5.15 struck me as pretty interesting. But then again, especially in the high-E_b/N_0 region, it's kind of questionable that the only non-CPM benchmark to compare against is a QPSK. At least higher-order classical PSKs should be considered (and if we don't demand the constant-envelope properties, we do have much higher-rate linear mods anyways). | |
| 22 hours ago | comment | added | Marcus Müller | Funilly, I've discussed something GMSK-related based on your 1. book with a colleague on Friday. However, citing a 1986 book for "modern communications" isn't very good an argument. CPM techniques can often be shown to stay pretty far away from Shannon limits, so that since that books doesn't address the spectral /error efficiency of CPM in comparison with modern high-dimensional mods, | |
| 22 hours ago | comment | added | Ali | In mobile comm when both power and bw are the concern, general CPM works well! You can take a look at these: 1- Anderson et. al, Digital Phase Modulation, 1986, p.113. 2- Xiong, Digital Modulation Techniques, 2ed, 2006, p.285. | |
| 22 hours ago | comment | added | Marcus Müller | depends; can't tell you. This is mostly down to your specific channel model, and the fact that you're working on CPM in 2024 means you're probably elbow-deep in the specifics of your channel model justifying CPM. So, my suspicion is that if it was justified, you'd just use a classical linear modulation and not CPM (general CPM, not some linear corner cases like GMSK). But this is just a guess. It's up to you to come clear how you end up with a FSM model to be able to use Viterbi at all, and I don't know your assumptions nor your model. | |
| 22 hours ago | comment | added | Ali | Thanks! I am involved in CPM and its trellis states. Now, is the claim OK? | |
| yesterday | history | edited | Marcus Müller | CC BY-SA 4.0 |
added 32 characters in body
|
| yesterday | history | answered | Marcus Müller | CC BY-SA 4.0 |