In solutions provided in embodiments of the present application, a second orthogonal basis vector group and a group number of the second orthogonal basis vector group are determined according to a pre-defined first basis vector group, a third orthogonal basis vector group corresponding to each data layer is determined according to the second orthogonal basis vector group, then a second-level code word of each data layer is calculated separately, and the group number of the second orthogonal basis vector group, the third orthogonal basis vector group corresponding to the each data layer, and the second-level code word corresponding to the each data layer are sent to a base station, so that the base station may synthesize a multi-layer code word.