Abstract: A projection apparatus includes a pixel array disposed on a substrate, where the pixel array has a light-emitting feature; a cantilever beam disposed on the substrate and configured to fasten a micro-electro-mechanical system (MEMS) lens, where the cantilever beam is disposed outside the pixel array, the MEMS lens is configured to scan the pixel array, the cantilever beam and the MEMS lens form a MEMS lens scanner; and a driver coupled to the pixel array and the MEMS lens and configured to drive the pixel array having a light-emitting feature to perform color display to obtain a projected image.

Abstract: A radar power control method and an apparatus are provided. The method includes: emitting a first detection signal at a target emission angle; obtaining a reflectivity of a first detection point of the first detection signal if signal power of an echo signal of the first detection signal is less than a preset power threshold, where the first detection point is a point on a surface of a detected object in a direction of the target emission angle; and increasing emission power corresponding to the target emission angle if the reflectivity of the first detection point is greater than a preset first threshold. The solution helps consider both power consumption and a detection distance of a radar.

Abstract: Embodiments of this application disclose a communication method and an apparatus, and relate to the communications field, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system. A specific solution is: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and sending the N physical frames by using the N light sources, where one light source sends one physical frame. The embodiments of this application are used in an optical camera communication process.

Abstract: A radar power control method and an apparatus are provided. The method includes: emitting a first detection signal at a target emission angle; obtaining a reflectivity of a first detection point of the first detection signal if signal power of an echo signal of the first detection signal is less than a preset power threshold, where the first detection point is a point on a surface of a detected object in a direction of the target emission angle; and increasing emission power corresponding to the target emission angle if the reflectivity of the first detection point is greater than a preset first threshold. The solution helps consider both power consumption and a detection distance of a radar.

Abstract: A method includes receiving X pilot symbols, determining light source sequence numbers of the X light sources based on the X pilot symbols, receiving M×X undersampled pulse width modulation-based pulse position modulation (UPPM) symbols and parsing the M×X UPPM symbols thereby obtaining original data from a sending node by using N light sources. Each of the X pilot symbols includes W waveform segments. Each of the W waveform segments includes a first light source sequence number indication part that indicates a light source sequence number. Waveforms of waveform segments with odd sequence numbers in the W waveform segments are the same, waveforms of waveform segments with even sequence numbers in the W waveform segments are the same, and a duration of each of the W waveform segments is equal. The X pilot symbols are in a one-to-one correspondence with X light sources.

Abstract: A data transmission method, device, and system includes, when a preset condition is met, determining a quantity N of first symbols included in one first symbol group and a quantity K of bits transmitted in the first symbol group, where the preset condition is ? log2 mN?>N·? log2 m?, K=? log2 mN?, m?2, N?2, and K?3; obtaining X data blocks, where each of the first X?1 data blocks includes K bits, the last data block includes Y bits, X?1, and K?Y?1; and processing each of the X data blocks into N first symbols to obtain NX first symbols, and sending the NX first symbols.

Abstract: Embodiments of this application relate to the communications field, disclose a camera communication method and an apparatus. A solution is: generating N pilot symbols and M×N UPPM symbols, where each of the N pilot symbols includes W waveform segments, each of the W waveform segments includes a first light source sequence number indication part used to indicate a light source sequence number, waveforms of waveform segments with odd sequence numbers in the W waveform segments are the same, waveforms of waveform segments with even sequence numbers in the W waveform segments are the same, and duration of each of the W waveform segments is equal; and sending the N pilot symbols and the M×N UPPM symbols by using the N light sources, where one light source is used to send one pilot symbol and M UPPM symbols. The embodiments of this application are used in an optical camera communication process.

Abstract: Embodiments of this application disclose a communication method and an apparatus, and relate to the communications field, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system. A specific solution is: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and sending the N physical frames by using the N light sources, where one light source sends one physical frame. The embodiments of this application are used in an optical camera communication process.

Abstract: A data transmission method, device, and system includes, when a preset condition is met, determining a quantity N of first symbols included in one first symbol group and a quantity K of bits transmitted in the first symbol group, where the preset condition is ?log2 mN?>N·?log2 m?, K=?log 2 mN?, m?2, N?2, and K?3; obtaining X data blocks, where each of the first X?1 data blocks includes K bits, the last data block includes Y bits, X?1, and K?Y?1; and processing each of the X data blocks into N first symbols to obtain NX first symbols, and sending the NX first symbols.

Abstract: A standing wave detection method, a standing wave detection apparatus, and a base station are disclosed. The method includes collecting, a feedback signal from a feedback path of a base station which uses a baseband multi-tone signal as a transmission signal; performing calibration on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal; and obtaining a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.

Abstract: A standing wave detection method, a standing wave detection apparatus, and a base station are disclosed. The method includes collecting, a feedback signal from a feedback path of a base station which uses a baseband multi-tone signal as a transmission signal; performing calibration on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal; and obtaining a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.