Abstract: Apparatuses, systems, and methods for providing beams for using deflector control to control charging on a sample surface of charged particle beam systems. In some embodiments, a controller including circuitry configured to scan a plurality of nodes of the sample to charge the plurality of nodes; adjust a scan rate of a beam such that a quantity of charge deposited on each node of the plurality of nodes varies with respect to at least one other node; generate a plurality of images; and compare the plurality of images to enable detection of a defect associated with any of the plurality of nodes of the sample.

Abstract: This application discloses a method including a transmit end that generates and sends a physical layer protocol data unit (PPDU), and a receive end that receives the PPDU and parses the PPDU. An enhanced directional multi-gigabit (EDMG) modulation field in the PPDU includes a channel estimation field (CEF), the CEF includes a CEF sequence, and a length of the CEF sequence is m, where m is determined based on a quantity of bonding channels and a quantity of subcarriers included on a channel. When a discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) technology is introduced into a 60 GHz WLAN standard, an applied CEF sequence included in a CEF can be determined, and DFT-S-OFDM transmission is further performed by using the CEF sequence. In this way, a PAPR of a WLAN system can be reduced while frequency division multiplexing for a plurality of users is supported.

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: In this application, a manner of generating a modulated field STF is enriched, so that a manner of generating a PPDU is enriched, thereby improving data transmission flexibility. The method includes: After generating a PPDU, a transmit end sends the PPDU to at least one receive end, where the PPDU includes at least one modulated field STF, the modulated field STF includes a plurality of zero elements and a plurality of non-zero elements, m1 zero elements are included before a first non-zero element, m2 zero elements are included after a last non-zero element, m1+m2 zero elements are included between any two adjacent non-zero elements, m1 and m2 both are positive integers, and the modulated field STF is mapped to a plurality of consecutive subcarriers for transmission. This application is used for data transmission.

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 surface-mounted transformer includes an adhesive layer and a winding product. The winding product is disposed inside the adhesive layer; the winding product includes an I-shaped magnetic core and a coil wound on a middle pillar of the I-shaped magnetic core; leading-out ends of the coil are connected to electrodes; the electrodes are exposed on the surface of the adhesive layer; and the adhesive layer is obtained through compression molding forming of a magnetic molding material. Compared with a surface-mounted transformer in the prior art, which has equal performance indexes, the surface-mounted transformer has a smaller size with a decrease proportion of over 50%; and a BOBBIN and an insulating rubber tape do not need to be used in processing. The winding product in the surface-mounted transformer is completely covered by the adhesive layer, so that the product is high in reliability and can support a PSIP plastic package environment.

Abstract: A method comprises: a transmit end generates and sends a physical layer protocol data unit (PPDU), and a receive end receives the PPDU and parses the PPDU. An enhanced directional multi-gigabit (EDMG) modulation field in the PPDU includes a channel estimation field (CEF), the channel estimation field (CEF) includes a CEF sequence, and a length of the CEF sequence is m, where m is determined based on a quantity of bonding channels and a quantity of subcarriers included on a channel. According to this application, when a DFT-S-OFDM technology is introduced into a 60 GHz WLAN standard, an applied CEF sequence included in a channel estimation field can be determined, and DFT-S-OFDM transmission is further performed by using the CEF sequence. In this way, a PAPR of a WLAN system can be reduced while frequency division multiplexing for a plurality of users is supported.

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: In this application, a manner of generating a modulated field STF is enriched, so that a manner of generating a PPDU is enriched, thereby improving data transmission flexibility. The method includes: After generating a PPDU, a transmit end sends the PPDU to at least one receive end, where the PPDU includes at least one modulated field STF, the modulated field STF includes a plurality of zero elements and a plurality of non-zero elements, m1 zero elements are included before a first non-zero element, m2 zero elements are included after a last non-zero element, m1+m2 zero elements are included between any two adjacent non-zero elements, m1 and m2 both are positive integers, and the modulated field STF is mapped to a plurality of consecutive subcarriers for transmission. This application is used for data transmission.

Abstract: A network service configuration method and a network management device, where the method includes obtaining, by a network management device, a terminal access port and an access parameter that is configured for the terminal access port and that is of a network service, determining a to-be-configured port according to the access parameter that is configured for the terminal access port and that is of the network service; generating a configuration instruction of the to-be-configured port, and sending the configuration instruction of the to-be-configured port to a to-be-configured network device. Hence, intervention from an administrator is not required, an error probability of network operation and maintenance may be reduced, efficiency of configuring a parameter of the network service is improved, and administrator time is saved.

Abstract: A first device as a buffer server in an Ethernet transmits a first buffer client querying packet from a port of enabling a distributed buffer function of the first device, receives a first buffer client registering packet from a second device through the port, and adds the second device into a distributed buffer group of the port. When the first device detects that a sum of sizes of packets entering the port and not transmitted reaches a preset first flow-splitting threshold in a first preset time period, the first device forwards a packet entering the port and not transmitted to a buffer client selected from the distributed buffer group of the port.

Abstract: Examples relate to a method and a device for wireless access authentication. The method is applied to an intelligent gateway which is previously associated with account information of a user. The intelligent gateway may receive an access authentication packet comprising an authentication identification indicating a terminal device; the intelligent gateway may construct an identity verification packet comprising an authentication identification indicating the terminal device and an association account identification indicating an account registered on the intelligent gateway; the intelligent gateway may send the identity verification packet to a cloud server; the intelligent gateway may permit a terminal device corresponding to authentication identification carried in a verification success packet returned by the cloud server to pass the access authentication.

Abstract: Embodiments of the present invention provide a signal transmission method and apparatus, which can implement fast initial time synchronization. The method includes: generating, by a transmit-end device, an initial short training sequence, where the initial short training sequence includes M sub-sequences b, and the sub-sequence b includes N transmission sampling points; determining a quantity of reception sampling points used by a receive-end device when the receive-end device performs autocorrelation processing; generating a symbol sequence according to the quantity of the reception sampling points, and generating a target short training sequence according to the symbol sequence and the initial short training sequence; and sending a target signal to the receive-end device, where a short training sequence field of the target signal carries a short training sequence symbol, and the short training sequence symbol is used to indicate the target short training sequence.