generating first indication information, a plurality of groups of second indication information, and a third indication information, wherein the first indication information indicates a plurality of frequency domain component vectors, wherein each group of the plurality of groups of second indication information corresponds to a spatial layer and a plurality of spatial domain component vectors, and is used to construct precoding vectors of the spatial layer in a plurality of frequency bands, wherein each piece of second indication information in each group corresponds to a spatial domain component vector in the plurality of spatial domain component vectors and indicates at least one of the plurality of frequency domain component vectors that corresponds to the spatial domain component vector, wherein the third indication information indicates the plurality of spatial domain component vectors, wherein the precoding vectors in the plurality of frequency bands are constructed by using a weighted sum of a plurality of spatial-frequency component vectors, wherein each spatial-frequency component vector in the plurality of spatial-frequency component vectors is constructed by using a spatial domain component vector in the plurality of spatial domain component vectors and a frequency domain component vector in at least one frequency domain component vector indicated by second indication information corresponding to the spatial domain component vector, wherein the first indication information indicates a start position K₂ of the plurality of frequency domain component vectors, and wherein the third indication information indicates a start position K₁ of the plurality of spatial domain component vectors; and

sending the first indication information, the plurality of groups of second indication information, and the third indication information.