Given an unknown OFDM symbol consisting of 9144 samples, interested to know the size of the FFT used in the TX/Number of bins.
Do not see how can this information be derived based on this data. As a result, have tried to analyze the time domain of the downsampled vectors, and detect samples that were removed by the downsampling process.
Seems that the third graph represents the original FFT size – 128, as the sample at 277 has not been witnessed before(fft=64,32), and is witnessed at higher sampling rates.
Wonder if this is correct and whether there is a more accurate approach to determine the FFT size used?