A method includes sending, by a communication apparatus, configuration information. The configuration information includes a quantity of cyclic shift positions that corresponds to each device, the quantity of cyclic shift positions is used to cyclically shift a perfect sequence, and quantities that are of cyclic shift positions and that correspond to devices used for completing different services are different. The method is applied to an ultra-wideband (UWB)-based wireless personal local area network system, a sensing system, and the like, including 802.15 series protocols, such as an 802.15.4a protocol, an 802.15.4z protocol, or an 802.15.4ab protocol. The method is further applied to a wireless local area network system that can support a next-generation WI-FI protocol of 802.11ax, such as 802.11be, Wi-Fi 7, or extremely high-throughput (EHT), and 802.11 series protocols, such as a next generation of 802.11be or WI-FI 8.