This application provides a signal transmission method and apparatus, a reflector, and a receiver. In one example method, a reflector receives W excitation signals, where W exciters may be configured to carry data and a reference signal that are reflected by the reflector; and the reflector reflects data and L reference signals to a receiver, where the L reference signals are respectively carried in L excitation signals in the W excitation signals, where W and L are both integers greater than or equal to 1, and L is less than or equal to W.