Abstract: A communication method and apparatus are provided. The method includes: receiving first indication information from a network device, where the first indication information indicates a first dimension; receiving a downlink reference signal from the network device, where the downlink reference signal is determined based on the first dimension and an uplink reference signal; and determining channel information based on the downlink reference signal. In the method, the network device and a terminal device each bear a part of a calculation amount and a part of calculation complexity. Therefore, a calculation amount and calculation complexity of channel estimation independently performed by the network device or the terminal device can be reduced, a system latency can be further shortened, and a throughput of a communication system can be improved.

Abstract: This application provides a channel measurement method and apparatus. The method includes: A terminal device obtains a first reference signal set and a second reference signal set, where the first reference signal set includes N first reference signals, the second reference signal set includes M second reference signals, and M and N are positive integers greater than or equal to 1. The terminal device may further perform channel measurement based on the first reference signal set to obtain first channel information, where a first dimension of the first channel information is less than a quantity of transmit antennas of a first device. The terminal device may further obtain second channel information based on the second reference signal set and the first channel information, where a first dimension of the second channel information is less than the quantity of transmit antennas of the first device.

Abstract: Embodiments of this application provide a communication method and a communication apparatus. The method includes: A first communication apparatus receives a first indication parameter. There is a correspondence between the first indication parameter and first codeword-to-layer mapping. The first communication apparatus determines the first codeword-to-layer mapping based on the first indication parameter. Based on the method, in embodiments of this application, codeword-to-layer mapping can be dynamically adjusted and/or indicated. For example, a terminal device may use different codeword-to-layer mapping at different moments. For another example, different terminal devices may use different codeword-to-layer mapping at a same moment.

Abstract: A method for designing a metalens used for an image sensor and an image sensor is provided, the method includes: S1. determining a target waveband; S2. according to the target waveband, determining an initial structure parameter and an initial material parameter of the unit cells; S3. optimizing the initial structure parameters of the unit cells and the initial material parameters of the unit cells, so as to obtain target parameters of unit cells; the target parameters of unit cells comprise: a phase of the unit cells and transmittance of the unit cells for an oblique incident light; S4: determining whether the transmittance of the metalens with the target structure parameter of unit cells meets the target transmittance.

Abstract: The present disclosure discloses a method and system for evaluating collision testing of a bottom of a battery pack and a device.