Timeline for Meaning of frequency and bandwidth of a signal, despite the fact that we do not know the signal
Current License: CC BY-SA 4.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| S May 14, 2021 at 7:09 | vote | accept | Anastassis Kapetanakis | ||
| May 14, 2021 at 7:02 | vote | accept | Anastassis Kapetanakis | ||
| S May 14, 2021 at 7:09 | |||||
| May 14, 2021 at 0:33 | answer | added | Envidia | timeline score: 1 | |
| May 14, 2021 at 0:08 | answer | added | OverLordGoldDragon | timeline score: 0 | |
| May 13, 2021 at 11:02 | comment | added | OverLordGoldDragon | @AnastassisKapetanakis I'll write an answer (possibly soon) clarifying further. | |
| May 13, 2021 at 11:01 | comment | added | OverLordGoldDragon | @MBaz I did downvote an answer; yours + comments is a fine complement to my response. I retract about 'dodging' if OP's satisfied, but I had this apparently same question before and your answer would miss my query. I also disagree regarding bandlimited. If this question is a first on this network, suppose I'll write an answer | |
| May 12, 2021 at 23:09 | comment | added | Anastassis Kapetanakis | @OverLordGoldDragon So what you suggest is that the conclusion we end up about the fact that our signal is bandlimited is just an approximation to reality? | |
| May 12, 2021 at 19:13 | comment | added | MBaz | @OverLordGoldDragon Thankfully DSP is an engineering discipline; it's not math or science. Following your premises, the DFT is as problematic as the CFT: no physical signal is band-limited, therefore they can't be sampled; no ideal sampler is physically realizable; no computer can carry out infinite-precision calculations. I also find it curious that you seem to prefer the DFT over the DTFT. Finally, if I'm wrong, downvote me or provide your own answer instead of asserting I'm dodging the question. | |
| May 12, 2021 at 17:11 | comment | added | OverLordGoldDragon | @MBaz Your comments do better, but DFT is critical. OP seeks to reconcile reasoning about an infinite interval from finite observation; limiting discussion to CFT makes the question unanswerable as CFT basis functions are physically unrealizable, unlike DFT's. It then remains to show we "extrapolate with reason" that our measured spectrum matches the infinite. | |
| May 12, 2021 at 14:44 | comment | added | MBaz | @OverLordGoldDragon I resent your assertion that I'm dodging the question; I'm answering as best as I can. Also, the DFT is not relevant, the question's context is the continuous-time domain. | |
| May 12, 2021 at 14:20 | comment | added | OverLordGoldDragon | Unsure I have time but the 'answers' are dodging your question; this is about DFT vs FT and attributing vs deriving meaning; relevant. Short version, $-\infty$ $+\infty$ is irrelevant, we measure from $t_0$ to $t_1$ and if some $f$ persists, we declare it as 'the frequency'. If a pendulum swings 3 times per sec you don't need to measure it for all eternity to be able to tell. As for freqs that change over time, that's a question of non-stationarity (for which we have STFT, CWT, etc). | |
| May 12, 2021 at 13:58 | answer | added | Hilmar | timeline score: 0 | |
| May 12, 2021 at 13:48 | answer | added | MBaz | timeline score: 1 | |
| May 12, 2021 at 13:36 | comment | added | Anastassis Kapetanakis | @OverLordGoldDragon What do you mean by saying that in my examples it's well defined? | |
| May 12, 2021 at 12:17 | comment | added | OverLordGoldDragon | Tricky stuff, beware of forcing a Fourier view. But in your examples it's well defined - someone will explain. | |
| May 12, 2021 at 9:50 | review | First posts | |||
| May 12, 2021 at 12:15 | |||||
| May 12, 2021 at 9:46 | history | asked | Anastassis Kapetanakis | CC BY-SA 4.0 |