The time to compute the inverse-FFT or FFT transform has to take less than the time for each symbol, which for example for DVB-T (FFT 8k) means the computation has to be done in 896 µs or less.
計算反FFT或FFT變換的時間必須少於每個符號的時間，例如對於DVB-T (FFT 8k) 意味著計算必須在896 μ s {\displaystyle \mu s} 或更短的時間內完成。