Timeline for How are subcarrier symbols modulated into an analog OFDM signal?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 17, 2023 at 10:50 | vote | accept | Cornelius | ||
| Oct 16, 2023 at 8:31 | comment | added | Cornelius | Yes, I am concerned with the bi- or even multistatic case. | |
| Oct 16, 2023 at 8:30 | comment | added | Marcus Müller | Anyways, that would only be relevant in a bistatic case. Let's hope that in the monostatic case, the clocks of your device are still the same frequency when the target reflections come back as they were when you were transmitting. | |
| Oct 16, 2023 at 8:28 | comment | added | Marcus Müller | CFO: pretty usual problem for ofdm receivers, typically solved by Schmidt&Cox. I'm not sure that's already in the book. SFO: if your radar TX and RX use the same reference clock to drive both the sampling frequency and the carrier/local oscillator frequency, detecting the carrier offset might be sufficient to detect the sampling frequency offset. | |
| Oct 16, 2023 at 8:22 | comment | added | Cornelius | Thank you! And thank you for the link to the book! :-) My final goal would be to model synchronization errors (regarding carrier frequency and regarding sampling) when using OFDM for radar. Maybe this is already in the book. | |
| Oct 16, 2023 at 8:19 | comment | added | Marcus Müller | Yep, we build cyclic prefixes on integer sample duration. "Bin length" is a bit of a misleading term, because bins exist in the frequency domain, but we're in time. Anyway , you mean the right thing because a (I)DFT just maps between complex vectors of the same length. Thus, your matrix looks correct. | |
| Oct 16, 2023 at 8:08 | comment | added | Cornelius | Re 1. & 2.: So, the digital domain should be $$ \mathbf z_{n_\mathrm s} = \mathbf J \mathbf F^\mathrm H \mathbf W_{n_\mathrm s} \mathbf s_{n_\mathrm s} $$ Where $\mathbf J$ is a selection matrix. $$ \mathbf J_\mathrm{CP} := \begin{bmatrix} \mathbf 0_{N_\mathrm G, (N_\mathrm C - N_\mathrm G)} & & \mathbf I_{N_\mathrm G} \\ & \mathbf I_{N_\mathrm C} & \end{bmatrix} $$ $N_\mathrm G$ is the number of IDFT bins to be included in the cyclic prefix. Correct? | |
| Oct 16, 2023 at 7:51 | comment | added | Cornelius | 1. & 2.: Okay, thanks. That implies that the length of the cyclic prefix is always an integer multiple of the IDFT bin length ($T_\mathrm D$). | |
| Oct 13, 2023 at 17:40 | history | edited | Marcus Müller | CC BY-SA 4.0 |
added 720 characters in body
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| Oct 13, 2023 at 17:34 | history | answered | Marcus Müller | CC BY-SA 4.0 |