Ernte1893
Newbie level 3
Hey guys,
I am trying to do a time & frequency synchronization for WirelessLAN connection with a OFDM (acutally non-contiguous OFDM). I reviewed the time synchronization and understood it. Schmidl used in his paper two identical training symbols as a preamble. Anyway, they just correlate these two and take the argument from the maximum value (long story short).
Anyway, at the moment I am struggeling with frequency synchronization. As mentioned, they apply preambles, which are built of two training symbols where each of them is built of two identical parts (for the correlation of time). However, for the frequency they take the phase difference between those two identical parts and calculate the frequency offset.
I understood the estimation, but why is a phase difference sufficient for the estimation of a frequency offset ? I mean, both of the parts are sent through the WLAN channel and might do have a different phase, but shouldn't they just be comparted with a non-changed reference ?
Thanks for your effort and help,
Toby
I am trying to do a time & frequency synchronization for WirelessLAN connection with a OFDM (acutally non-contiguous OFDM). I reviewed the time synchronization and understood it. Schmidl used in his paper two identical training symbols as a preamble. Anyway, they just correlate these two and take the argument from the maximum value (long story short).
Anyway, at the moment I am struggeling with frequency synchronization. As mentioned, they apply preambles, which are built of two training symbols where each of them is built of two identical parts (for the correlation of time). However, for the frequency they take the phase difference between those two identical parts and calculate the frequency offset.
I understood the estimation, but why is a phase difference sufficient for the estimation of a frequency offset ? I mean, both of the parts are sent through the WLAN channel and might do have a different phase, but shouldn't they just be comparted with a non-changed reference ?
Thanks for your effort and help,
Toby
