Abstract: This application relates to communication methods and apparatuses. In an example method, a first communication apparatus generates first indication information, and sends the first indication information to a second communication apparatus. The first indication information indicates M orbital angular momentum (OAM) modes jointly supported by the first communication apparatus and the second communication apparatus, where there is a correspondence between N OAM modes in the M OAM modes and a demodulation reference signal (DMRS) port.

Abstract: An antenna includes: a dielectric plate provided with a first surface and a second surface; a ground plane located on the first surface; and an antenna unit. A size of the antenna unit is a preset length, the antenna unit includes at least three antenna elements in a ring arrangement, and each antenna element includes a first patch, a second patch, and a third patch that are located on the second surface, and three conductive portions that penetrate through the first surface and the second surface.

Abstract: A Flettner rotor that employs localized suction over its surface improves performance and fuel efficiency. Simulations and analysis show that such a method can significantly improve the performance of the Flettner rotor. Improvements in rotor performance enable reduction in fuel costs and greenhouse gas emission by ships or other modes of transport. Improvements in rotor performance can also reduce noise for applications such as drones or other devices having rotors.

Abstract: A method includes sending a first orbital angular momentum (OAM) reference signal in a first beam direction. The first OAM reference signal is used to determine a second beam direction from the first beam direction. The method also includes receiving first indication information. The first indication information includes information about the second beam direction. The method also includes sending a second OAM reference signal in the second beam direction. The second OAM reference signal is used to determine antenna information and a second channel response of the second OAM reference signal. The method also includes receiving second indication information. The second indication information is determined based on the second channel response and the antenna information. The second indication information is used to determine a transmission manner. The transmission manner includes OAM wave transmission, plane wave transmission, or joint transmission of OAM and a plane wave.

Abstract: A radio resource identification method and an apparatus. The method includes: obtaining OAM mode domain information, where the OAM mode domain information includes a first OAM mode domain identifier, the first OAM mode domain identifier corresponds to a first transmission parameter of a vortex electromagnetic wave in a first OAM physical mode, or the first OAM mode domain identifier corresponds to a first ratio between the first transmission parameter and a reference value, and the reference value includes a transmission parameter of a plane electromagnetic wave or a transmission parameter of a vortex electromagnetic wave in a specified OAM physical mode in a plurality of OAM physical modes; and any plurality of waveform symbols pass through a same vortex electromagnetic wave channel; and determining a radio resource used for uplink transmission or downlink transmission.

Abstract: A quantum communication method, an apparatus, and a system are provided. The method includes: modulating a first symbol to an ith direction vector of a first electric wave based on a preset mapping relationship, to obtain a second electric wave; and transmitting the second electric wave, where the first electric wave supports M direction vectors, the ith direction vector of the first electric wave is one of the M direction vectors of the first electric wave, the first symbol is a symbol corresponding to first data, the ith direction vector of the first electric wave corresponds to an ith distribution result, the ith distribution result is obtained by converting the second electric wave into an energy quantum. The first symbol may be modulated to a direction vector of the first electric wave, and this application is compatible with the conventional technology.

Abstract: The present disclosure relates to precoding matrix determining methods, devices, and systems. In one example method, a receive end device obtains channel state information (CSI) of a first channel and information about P antenna port groups of a transmit end device. The receive end device determines V orbital angular momentum (OAM) mode groups based on the CSI of the first channel and first OAM modes, determines a first precoding matrix based on the P antenna port groups of the transmit end device and the V OAM mode groups, and sends, to the transmit end device, first indication information indicating the first precoding matrix. The transmit end device receives the first indication information, and determines the first precoding matrix based on the first indication information.

Abstract: A Cassegrain or quasi-Cassegrain structure objective lens is used in a polar MOKE metrology system. The quasi-Cassegrain reflective objective lens includes a primary concave mirror and a secondary mirror. The primary concave mirror has a wider diameter than the secondary mirror and defines an aperture through which the laser beam is configured to be transmitted toward the secondary mirror. The secondary mirror can be convex, concave, or have a flat surface.

Abstract: This application provides a quantum communication method, an apparatus, and a system. The method includes: modulating a first symbol to an ith direction vector of a first electric wave based on a preset mapping relationship, to obtain a second electric wave; and transmitting the second electric wave, where the first electric wave supports M direction vectors, the ith direction vector of the first electric wave is one of the M direction vectors of the first electric wave, the first symbol is a symbol corresponding to first data, the ith direction vector of the first electric wave corresponds to an ith distribution result, the ith distribution result is obtained by converting the second electric wave into an energy quantum. In this application, the first symbol may be modulated to a direction vector of the first electric wave, and this application is compatible with the conventional technology.

Abstract: A laser beam is directed through a transmissive axicon telescope or a reflective axicon telescope such as in a magneto-optic Kerr effect metrology system. With the transmissive axicon telescope, a Gaussian beam profile is directed through a first axicon lens and a second axicon lens. The first axicon lens and second axicon lens transfer the Gaussian beam profile of the laser beam to a hollowed laser ring. The laser beam with a hollowed laser ring can be directed through a Schwarzschild reflective objective. With the reflective axicon telescope, the laser beam is directed through two conical mirrors that are fully reflective. One of the conical mirrors defines a central hole that the laser beam passes through.

Abstract: The present disclosure describes example communication methods, terminals, access network devices, and core network devices. One example communication method includes sending, by an access network device, a slice resource adjustment message to a terminal, where the slice resource adjustment message includes target resource information, and wherein the slice resource adjustment message is used to instruct the terminal to adjust a resource of a slice currently accessed by the terminal to the target resource. The access network device receives a slice resource adjustment complete message sent by the terminal, where the slice resource adjustment complete message is used to indicate that the terminal has adjusted the resource of the slice currently accessed by the terminal to the target resource.

Abstract: A virtual reality (VR) based driving simulation system and method provides hazard perception training and testing. Some embodiments use a personal computing device (e.g., smartphone), a head-mounted VR headset, and a Bluetooth-connected push button keypad or other user input device. An immersive, 3D simulator enables users to experience and learn from hazardous scenarios without risking injury. Performance by a user in perceiving a hazard is compiled as a metric in a user profile stored on a server, and continued training and testing can be conducted with updated scenarios supplied by the server in accordance with the metric associated with a user.

Abstract: A laser beam is directed through a transmissive axicon telescope or a reflective axicon telescope such as in a magneto-optic Kerr effect metrology system. With the transmissive axicon telescope, a Gaussian beam profile is directed through a first axicon lens and a second axicon lens. The first axicon lens and second axicon lens transfer the Gaussian beam profile of the laser beam to a hollowed laser ring. The laser beam with a hollowed laser ring can be directed through a Schwarzschild reflective objective. With the reflective axicon telescope, the laser beam is directed through two conical mirrors that are fully reflective. One of the conical mirrors defines a central hole that the laser beam passes through.

Abstract: Embodiments provide a network communication method, including obtaining, by a second convergence control apparatus after receiving an indication message sent by a first convergence control apparatus, a preset proportion of service data from service data that the first convergence control apparatus needs to transmit and performing, by the second convergence control apparatus, parameter matching on the preset proportion of service data according to a system parameter of a current communications standard The method also includes transmitting, by the second convergence control apparatus, the matched preset proportion of service data by using a corresponding data link layer. The embodiments further disclose a network communications apparatus.

Abstract: The present disclosure describes example communication methods, terminals, access network devices, and core network devices. One example communication method includes sending, by an access network device, a slice resource adjustment message to a terminal, where the slice resource adjustment message includes target resource information, and wherein the slice resource adjustment message is used to instruct the terminal to adjust a resource of a slice currently accessed by the terminal to the target resource. The access network device receives a slice resource adjustment complete message sent by the terminal, where the slice resource adjustment complete message is used to indicate that the terminal has adjusted the resource of the slice currently accessed by the terminal to the target resource.

Abstract: Embodiments of this application provide a control information sending method and apparatus, where the method includes: obtaining a control information indication message from a first standard network, selecting a second standard network from one or more other networks that constitute a heterogeneous network with the first standard network, and sending the control information indication message to the second standard network, and then to a client over the second standard network. The control information indication message is used to instruct to substitutively send control information of the first standard network. According to the method and apparatus provided, the control information of the first standard network is substitutively sent over the second standard network, and sending the control information does not need to occupy bandwidth of the first standard network. Therefore, in comparison with the prior art, a network capacity of service data sent over the first standard network can be increased.

Abstract: Embodiments provide a data sending method and device. The data sending method includes: determining, by a transmitting device, a busy/idle state of a wireless communications channel and a communication status of a receiving device before sending data to the receiving device, where the transmitting device is a wireless access node or the transmitting device is a station, and the receiving device is a wireless access node or the receiving device is a station. The method also includes sending, by the transmitting device, the data to the receiving device if the wireless communications channel is in a busy state and the receiving device is in an idle communication state.

Abstract: A wireless network control apparatus including a receiver configured to obtain a network information of a first-standard network, a processor configured to determine an instruction information which includes the network information that is of the first-standard network and that is obtained by the receiver, and a transmitter, configured to send the instruction information determined by the processor to a second-standard network, so that the second-standard network sends the network information of the first-standard network to a terminal, where the terminal works in the second-standard network.

Abstract: Embodiments of the present invention provide a data transmission method, a sender device, and a receiver device. The method includes: sending, by a sender device, to-be-transmitted data to a receiver device according to a transmission policy; and receiving, by the sender device, feedback information sent by the receiver device. In this process, for to-be-transmitted data after a guard interval in a last radio frame of any scheduling window, the sender device sends the to-be-transmitted data according to the transmission policy, so that no timeout occurs when the sender device is waiting for the feedback information, thereby achieving an objective of improving data transmission efficiency.

Abstract: Embodiments disclose a multiple-communications-standard transmission method and apparatus. The method includes when both a WLAN communications standard and a wireless cellular communications standard are available, sending, by a transmit end supporting multiple communications standards by preferentially using the WLAN communications standard, a service flow of a service session to a receive end supporting multiple communications standards. The method also includes in response to that a first switch condition is met, switching, by the transmit end at a data link layer, to using the wireless cellular communications standard for continuous transmission of the service flow, where the first switch condition includes at least that a WLAN communication link fails in communication.