Patent ID: 7796577

Claim:
An operation schedule design method for a fast Fourier transform (FFT) apparatus, comprising: setting an operation speed of an FFT/Inverse FFT (IFFT) operator performing an FFT operation and an IFFT operation to be higher than a data transmission speed; arranging a receiving Orthogonal Frequency Division Multiplexing (OFDM) symbol in a first FFT schedule in order that the receiving OFDM symbol may be demodulated after receiving the receiving OFDM symbol from a channel; arranging a transmitting OFDM symbol in the FFT schedule in order that the transmitting OFDM symbol may be generated before transmitting the transmitting OFDM symbol to the channel; filling a first FFT schedule by inserting symbols into idle durations of the first FFT schedule, wherein the inserted symbols belong to OFDM symbol durations of a second FFT schedule which have the same timing as the first FFT schedule; determining whether scheduling for all symbols is possible when a part of a plurality of FFT schedules is deleted; deleting FFT schedules of as many as or less than the number of FFT schedules which is determined to be possible to delete in the determining of whether scheduling for all symbols is possible; and re-arranging symbols of the deleted FFT schedules, in non-deleted FFT schedules in order to not have an error occur in symbol transmitting/receiving timing.