Could someone please explain how the 4G LTE OFDM measures and corrects the sampling frequency offset?
I can see a number of algorithms proposed in the literature, but I am trying narrow it down to the actually implemented ones.
Thanks in advance.
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I am not a specialist of the 4G LTE, but worked on other OFDM waveform similar to it.
OFDM signal is made of symbols. Each symbol in frequency domain is made of a number of subcarriers. Some of subcarriers are mapped with data and other with pilots.
Pilots have known defined values (usually scrambled BPSK symbols). The sampling frequency offset results in phase shift of the same pilot from one OFDM symbol to the next one (or next ones).
After computing the phase shift, it can be used as a timing error of a digital phase locked loop acting on the resampler of the demodulation system.
You could try to analyze the behavior of pilots with sampling offset if you have a MAtlab model.