An example terminal device receives resource scheduling information sent by a network device, where the resource scheduling information is used to indicate a second resource set allocated by the network device, where the second resource set includes at least one resource block which is from a first resource set, and where the first resource set is an integer quantity of resource blocks that are evenly distributed in frequency domain. The terminal device can then perform uplink transmission on a detected idle frequency domain resource based on the resource scheduling information, where the uplink transmission occupies a plurality of time units, where a resource structure of a resource block used for the uplink transmission in each time unit is the same as a resource structure of the second resource set, and where frequency locations of resource blocks used for the uplink transmission in adjacent time units are different.