This disclosure discloses methods and apparatuses for signal processing. In an implementation, a method comprises: generating first indication information, wherein the first indication information indicates L1 space domain vectors in a space domain vector set, K1 frequency domain vectors in a frequency domain vector set, and T1 space-frequency component matrices, wherein a precoding vector of one or more frequency domain units is determined by a weighted sum of the T1 space-frequency component matrices, wherein the L1 space domain vectors and the K1 frequency domain vectors correspond to M1 space-frequency component matrices that comprise the T1 space-frequency component matrices, wherein each of the M1 space-frequency component matrices is uniquely determined by a different combination of one of the L1 space domain vectors and one of the K1 frequency domain vectors; and sending the first indication information.