This application relates to the field of wireless communications and self-driving/intelligent driving, and in particular, to the field of collaborative radars. In a solution of this application, a first apparatus receives first information from a second apparatus; the first apparatus determines, based on the first information, priorities of a plurality of time-frequency resources included in a first time-domain range; and the first apparatus determines a first time-frequency resource in the plurality of time-frequency resources, where a priority of the first time-frequency resource is not lower than a priority of a time-frequency resource other than the first time-frequency resource in the plurality of time-frequency resources. A time-frequency resource with a comparatively high priority is selected to send a radar signal, to reduce a probability of a resource collision, and reduce or avoid interference between radars, especially collaborative radars.