The present invention provides a signal determining method and an apparatus, so as to resolve a problem, in a conventional positioning method, that a signal receiving device cannot accurately determine whether a received signal is an aggregated reference signal, and consequently, positioning fails due to a relatively large error of location information obtained by means of positioning. The method is as follows: A signal receiving device may estimate, according to a TAE between at least two subcarriers used by a signal sending device to transmit a reference signal and a reference signal sent by the signal sending device on each subcarrier, an aggregated reference signal that is sent by the signal sending device and that is obtained after carrier aggregation. After receiving a signal, the signal receiving device determines whether the signal is an aggregated reference signal sent by the signal sending device.