The present disclosure relates to signal transmission methods, devices, and systems. One example method includes sending, by a network device, a plurality of synchronization signal/physical broadcast channel (SS/PBCH) blocks in one or more burst set windows, where the one or more burst set windows include a plurality of candidate positions that are used to transmit the plurality of SS/PBCH blocks. SS/PBCH blocks sent at positions corresponding to at least two particular indexes have a quasi co-located (QCL) relationship.