A data transmission method, comprising: generating a preamble for a protocol version of a wireless local area network, wherein the preamble comprises a high efficiency signal HE-SIG field, the HE-SIG field comprises a first orthogonal frequency division multiplexing OFDM symbol, a second OFDM symbol, a third OFDM symbol and a fourth OFDM symbol, wherein the four symbols are arranged in order, and input information bits of the first OFDM symbol are the same as that of the second OFDM symbol, and input information bits of the third OFDM symbol are the same as that of the fourth OFDM symbol; wherein the input information bits of the third and fourth OFDM symbols include all left information bits except the input information bits of the first and second OFDM symbols, in information bits that need to be carried in the HE-SIG field, wherein the generating a preamble comprises: processing the input information bits of the first and second OFDM symbol, by using a channel encoder, an interleaver, and a first modulator to obtain the first OFDM symbol; and, by using the channel encoder, without interleaving, and a second modulator to obtain the second OFDM symbol, wherein the first modulator and the second modulator are same or different; processing the input information bits of the third and fourth OFDM symbol, by using the channel encoder, the interleaver, and a third modulator to obtain the third OFDM symbol; and, by using the channel encoder, without interleaving, and a fourth modulator to obtain the fourth OFDM symbol, wherein the third modulator and the fourth modulator are same or different; and sending the preamble to a receive end device. generating a preamble for a protocol version of a wireless local area network, wherein the preamble comprises a high efficiency signal HE-SIG field, the HE-SIG field comprises a first orthogonal frequency division multiplexing OFDM symbol, a second OFDM symbol, a third OFDM symbol and a fourth OFDM symbol, wherein the four symbols are arranged in order, and input information bits of the first OFDM symbol are the same as that of the second OFDM symbol, and input information bits of the third OFDM symbol are the same as that of the fourth OFDM symbol; wherein the input information bits of the third and fourth OFDM symbols include all left information bits except the input information bits of the first and second OFDM symbols, in information bits that need to be carried in the HE-SIG field, wherein the generating a preamble comprises: processing the input information bits of the first and second OFDM symbol, by using a channel encoder, an interleaver, and a first modulator to obtain the first OFDM symbol; and, by using the channel encoder, without interleaving, and a second modulator to obtain the second OFDM symbol, wherein the first modulator and the second modulator are same or different; processing the input information bits of the third and fourth OFDM symbol, by using the channel encoder, the interleaver, and a third modulator to obtain the third OFDM symbol; and, by using the channel encoder, without interleaving, and a fourth modulator to obtain the fourth OFDM symbol, wherein the third modulator and the fourth modulator are same or different; and sending the preamble to a receive end device. processing the input information bits of the first and second OFDM symbol, by using a channel encoder, an interleaver, and a first modulator to obtain the first OFDM symbol; and, by using the channel encoder, without interleaving, and a second modulator to obtain the second OFDM symbol, wherein the first modulator and the second modulator are same or different; processing the input information bits of the third and fourth OFDM symbol, by using the channel encoder, the interleaver, and a third modulator to obtain the third OFDM symbol; and, by using the channel encoder, without interleaving, and a fourth modulator to obtain the fourth OFDM symbol, wherein the third modulator and the fourth modulator are same or different; and sending the preamble to a receive end device.