Data processing apparatus and data processing method

A data processing method of a data processing apparatus, the method comprising:

• performing modulation processing on a physical layer frame including a preamble and plural subframes,
• wherein different fast Fourier transforms (FFT) sizes are respectively set for at least two of the subframes,
• the subframes are arranged in the physical layer frame in contiguous subframe groups, each subframe group of the contiguous subframe groups including all subframes of the physical layer frame with a same FFT size at least one subframe group of the contiguous subframe groups including plural subframes with the same FFT size, when IFFT operation is performed on symbols included in the physical layer frame, and
• an FFT size of the preamble of the physical layer frame is less than or equal to an FFT size of subframes in a subframe group immediately following the preamble.

A data processing apparatus comprising:

• circuitry configured to perfoiui demodulation processing on a physical layer frame including a preamble and plural subframes,
• wherein different fast Fourier transform (FFT) sizes are respectively set for at least two of the subframes,
• the subframes are arranged in the physical layer frame in contiguous subframe groups, each subframe group of the contiguous subframe groups including all subframes of the physical layer frame with a same FFT size, at least one subframe group of the contiguous subframe groups including plural subframes with the same FFT size, when fast Fourier transform (FFT) operation is performed on symbols included in the physical layer frame, and
• an FFT size of the preamble of the physical layer frame is less than or equal to an FFT size of subframes in a subframe group immediately following the preamble.