This application relates to the field of wireless communications and self-driving/intelligent driving/autonomous driving vehicles, and in particular, to the field of collaborative radars. A first apparatus receives first information from a second apparatus. The first apparatus determines, based on the first information, the priorities of a plurality of time-frequency resources included in a first time-domain range. The first apparatus further selects a first time-frequency resource among the plurality of time-frequency resources. The priority of the first time-frequency resource is the highest among the priorities of 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 and/or avoid interference between radars, especially collaborative radars.