This application discloses a data sending method, a signaling sending method, an apparatus, and a system, and relates to the communications field. The method includes: receiving, by a terminal, a downlink reference signal sent by an access network device; measuring, by the terminal, the downlink reference signal, to obtain a plurality of uplink precoding vectors; sending, by the terminal, SRSs to the access network device on a plurality of uplink SRS resources, where SRSs sent on different uplink SRS resources are precoded by using different uplink precoding vectors; receiving, by the terminal, uplink scheduling signaling sent by the access network device, where the uplink scheduling signaling is used to indicate a resource index of at least one uplink SRS resource.