I'm trying to understand how symbol synchronization is done in OFDM using pilot tones, cyclic prefixes, or any other technique.
I've read the following answers which provide some explanation, but I still don't totally understand it.
How to demodulate an OFDM signal
How to estimate the number of taps needed for subsequent channel estimation algorithms?
Specific questions:
1) How is a pilot tone found? What makes it different than the regular data on a sub-carrier? How can it be used to determine symbol starts and ends?
2) If I understand the answers above correctly, a cyclic prefix can be used to find the symbol start/end because it will auto-correlate with some delay. However, the cyclic-prefix exists in order to "absorb" ISI. So if the prefix has been munged with ISI, then how can this auto-correlation be successful?
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