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Is the sample rate for OFDM equal to the FFT rate?
The sample rate for OFDM is exactly equal to the sample rate that the OFDM transmitter used when it inverse FFT’ed the data. No, the sample rate has nothing to do with the modulation types used inside the OFDM symbols (e.g. BPSK or QPSK).
What is the relation between FFT length and sample length?
Then, our frequency bin resolution is: This is may be the easier way to explain it conceptually but simplified: your bin resolution is just , where is the input signal’s sampling rate and N is the number of FFT points used (sample length).
How is F ft size related to FFT size?
The F FT size defines the number of bins used for dividing the window into equal strips, or bins. Hence, a bin is a spectrum sample, and defines the frequency resolution of the window. For a 44100 sampling rate, we have a 22050 Hz band. With a 1024 FFT size, we divide this band into 512 bins.
If the clock is raised to 10.24 Khz, we will get 400 lines spaced 10 Hz apart from a 1024 point FFT up to 4000 Hertz. We can slow the sample rate down to get more resolution at the expense of bandwidth or reduce the FFT size to get less resolution without sacrificing bandwidth.
How to demodulate the OFDM signal using modulated symbols?
Demodulate the OFDM symbols. Compare the results to the original input data to show that there is negligible difference between the demodulated signal and the original data and pilot signals. Modulated OFDM symbols, specified as a 2-D array of complex symbols.
Why do demodulators use a higher sample rate?
Demodulators almost always use a sample rate that is higher than the bandwidth for two reasons: to ensure that all of the signal is captured rather than aliased due to Nyquist frequency limitations, and to do some version of early/late gating when syncing with the symbols.
What kind of FFT operation is used in OFDM?
The OFDM demodulation uses an FFT operation that results in N parallel data streams. An OFDM demodulator consists of a bank of N correlators, with one correlator assigned to each OFDM subcarrier, followed by a parallel-to-serial conversion. Subcarrier Allocation and Guard Bands