Timeline for Time-frequency synchronization algorithm for OFDM continuous stream
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 25, 2015 at 18:05 | vote | accept | Alex2014 | ||
| Feb 9, 2015 at 10:32 | comment | added | Deve | A training sequence is generally used for timing synchronization, carrier frequency offset estimation and channel estimation. If all those parameters are estimated blindly the training sequence (TS) can be omitted. I think this is rarely done because blind estimation methods are less robust and computationally more complex. In contrast, training sequences introduce a relatively small overhead. If you compare it to the FEC overhead which is easily 100% in wireless systems, the TS overhead is negligible. | |
| Feb 9, 2015 at 10:19 | comment | added | Alex2014 | Yes, you're absolutely right, of course one needs some frame sync algorithm to demodulate meaningful data, to apply FEC, etc. But suppose you could reach this synchronization in a different way (e.g. using binary data formatting), would a training sequence still be needed? I mean, being used in packet data systems of course it has better performance, but would you really need it even in a continuous stream system, in which you can leverage the continuous transmission/reception of data? I still have doubts on this point. | |
| Feb 6, 2015 at 17:18 | comment | added | Deve | Yes. When using methods based on the guard interval only symbol synchronization (also called FFT window sync) can be achieved but not frame synchronization. However, in order to distinguish payload data and training sequences you have to know where a frame begins. | |
| Feb 6, 2015 at 17:11 | comment | added | Alex2014 | Thanks Deve. Actually I also know that several continuous stream systems (e.g. DVB-T/2) use periodic training sequences to reach frame and frequency sync. If I got your point, from your experience guard interval methods are better used to improve sync performance in the short period (say between a training sequence and the other)? If so, can you explain why? | |
| Feb 6, 2015 at 9:21 | history | answered | Deve | CC BY-SA 3.0 |