Abstract: An angular domain channel estimation method based on matrix reconstruction for a symmetrical nonuniform array is a combined two-stage channel estimation and channel equalization scheme provided based on an SNLA model. In a first stage, a matrix reconstruction method is used to estimate a path AOA, and compared with traditional channel estimation based on ULA, the matrix reconstruction method achieves a higher resolution ratio. In a second stage, an LS method is used to obtain a path gain. According to the angular domain channel estimation method, a mean square error of channel estimation, a bit error of data transmission and complexity of a traditional scheme are significantly reduced. A simulation result indicates that compared with the traditional method, the angular domain channel estimation method can achieve a lower MSE and BER.

Abstract: An angular domain channel estimation method based on matrix reconstruction for a symmetrical nonuniform array is a combined two-stage channel estimation and channel equalization scheme provided based on an SNLA model. In a first stage, a matrix reconstruction method is used to estimate a path AOA, and compared with traditional channel estimation based on ULA, the matrix reconstruction method achieves a higher resolution ratio. In a second stage, an LS method is used to obtain a path gain. According to the angular domain channel estimation method, a mean square error of channel estimation, a bit error of data transmission and complexity of a traditional scheme are significantly reduced. A simulation result indicates that compared with the traditional method, the angular domain channel estimation method can achieve a lower MSE and BER.

Abstract: A data transmission method. A physical layer protocol data unit (PPDU) is generated. The PPDU includes a training field. The training field includes a sequence used for target sensing. The PPDU is sent.

Abstract: This application relates to the field of communications technologies, and discloses a data transmission method. The method includes: generating a PPDU; and transmitting the PPDU to at least one receive end. The PPDU includes a channel estimation field CEF, and the CEF includes a plurality of sub-sequences. For each of the plurality of sub-sequences, a part or all of elements in the sub-sequence are basic elements, and the basic elements are arranged into a Golay sequence or a ZC sequence in the sub-sequence. This application is used for data transmission.

Abstract: An example physical layer protocol data unit (PPDU) transmission method includes generating, by a first communication device, a PPDU, where the PPDU includes a long training field (LTF) sequence. The first communication device can send the PPDU. A second communication device can receive the PPDU. The second communication device can parse the received PPDU to obtain the LTF sequence included in the PPDU.

Abstract: Embodiments of this application provide a method and an apparatus for transmitting a physical layer protocol data unit, to design a short training field sequence for a larger channel bandwidth. The short training field sequence designed in this application has a smaller peak-to-average power ratio PAPR and better performance. The method includes: generating a physical layer protocol data unit PPDU that complies with the 802.11be standard, where the PPDU includes a short training field, and a quantity of subcarriers of a frequency domain sequence of the short training field is greater than 2048; and sending the PPDU on a target channel, where a bandwidth of the target channel is greater than or equal to 160 MHz.

Abstract: This application provides a method and apparatus for transmitting a physical layer protocol data unit, so as to design a long training field sequence for a larger channel bandwidth. The method includes: generating a physical layer protocol data unit PPDU, where the PPDU includes a long training field, a length of a frequency domain sequence of the long training field is greater than a first length, and the first length is a length of a frequency domain sequence of a long training field of a PPDU transmitted over a channel whose bandwidth is 160 MHz; and sending the PPDU over a target channel, where a bandwidth of the target channel is greater than 160 MHz.

Abstract: Example methods for transmitting a physical layer protocol data unit (PPDU) and apparatus are described. One example method includes generating and transmitting a PPDU that includes a long training field (LTF). A length of a frequency-domain sequence of the LTF is greater than a first length, and the first length is a length of a frequency-domain sequence of an LTF of a first PPDU transmitted over a channel whose bandwidth is 160 MHz.

Abstract: A sequence generation method, includes: generating a PPDU which comprises a matrix-mapped EHT LTF sequence, the matrix-mapped EHT LTF sequence is obtained by multiplying a predefined EHT LTF sequence by a P matrix, the P matrix is an n×n matrix, and n is greater than 8; and sending the PPDU, therefore the matrix-mapped EHT LTF sequence in a PPDU has a low PAPR value.

Abstract: This application relates to the field of communications technologies, and discloses a data transmission method. The method includes: generating a PPDU; and transmitting the PPDU to at least one receive end. The PPDU includes a channel estimation field CEF, and the CEF includes a plurality of sub-sequences. For each of the plurality of sub-sequences, a part or all of elements in the sub-sequence are basic elements, and the basic elements are arranged into a Golay sequence or a ZC sequence in the sub-sequence. This application is used for data transmission.

Abstract: This application provides a data transmission method and a communications apparatus. The method includes: generating, by an access point, a physical protocol data unit PPDU, where a data part of the PPDU is carried on at least one resource unit RU; sending, by the access point, the PPDU to at least one station by using a channel bandwidth, where the channel bandwidth includes M basic bandwidths, the basic bandwidth is 2.16 GHz, M is an integer greater than or equal to 1, and the M basic bandwidths are divided into the at least one RU; and parsing, by the station, the data part that is of the PPDU and that is carried on the at least one RU. In embodiments of this application, it can implement an OFDMA technology in a high-frequency scenario, and improve channel utilization and transmission efficiency.