Generation method of preamble symbols and generation method of frequency-domain OFDM symbols

The invention discloses a generation method of frequency-domain OFDM symbols and a generation method of preamble symbols in physical frames. The generation method of the frequency-domain OFDM symbols includes the following steps that: the average power ratio of a fixed sequence and a signaling sequence is determined; fixed sequences and a signaling sequence set are respectively generated in the frequency domain according to the average power ratio R; one signaling sequence is selected from the signaling sequence set, and the fixed sequences and the signaling sequences fill effective sub carriers, odd-even staggered arrangement exists between the fixed sequences and the signaling sequences; two sides of the effective sub carriers are filled with zero-sequence sub carriers respectively to form a frequency domain OFDM symbol with a preset length; and the serial number of the selected signaling sequence in the set is the signaling information carried by OFDM symbols. With the generation methods provided by the technical scheme of the invention adopted, the problem of failure probability in low-complexity receiving algorithm detection on preamble symbols in a frequency selective fading channel in the current DVB_T2 standard and other standards can be solved.