Abstract: A communication method includes generating a first sequence, where the first sequence is based on a complete complementary code set, the complete complementary code set is based on a Golay pair and a Hadamard matrix through a Kronecker product operation, and the first sequence is used for channel estimation; and sending the first sequence. In the method, use of a P-matrix is avoided in a process of constructing a plurality of streams of zero correlation sequences.

Abstract: This application provides a sounding frame transmission method and a related apparatus. The method is applied to a first device, and the method includes: generating a sounding frame, where the sounding frame includes a first field, the first field includes a predefined first sequence, the first sequence includes a sequence obtained after a second sequence is modulated by using at least one of the following modulation modes, and the modulation modes include: QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and 4096-QAM; and sending the sounding frame. In this way, channel quality of a communication link in at least one of modulation modes of QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and 4096-QAM can be accurately measured when channel measurement is performed by using the first sequence, thereby enriching application scenarios of an EHT-LTF sequence.

Abstract: A long training field sequence transmission method and apparatus are provided, to send an LTF sequence on a discrete RU, and reduce a PAPR. The method includes: A STA determines an first LTF sequence, the first LTF sequence is a sequence segment that is in a total LTF sequence corresponding to a channel bandwidth and that corresponds to a first RU, N subcarriers in the channel bandwidth are in a one-to-one correspondence with N components of the total LTF sequence, the first RU is M consecutive first subcarriers in the N subcarriers, the first LTF sequence is M components in the N components; and the STA sends the first LTF sequence to an AP on a discrete RU, where the discrete RU includes M inconsecutive second subcarriers, and the M components of the first LTF sequence are respectively sent on the M inconsecutive second subcarriers.