A method and devices are provided. The method includes transmitting, by a first base station, a superposition of a codeword of first information and a codeword of second information to N terminals, where the first information and the second information correspond to each terminal of the N terminals, and N is a positive integer; and a codeword of first information corresponding to the rth terminal is obtained according to a transmit rate and a transmit power for the codeword of the first information corresponding to the rth terminal, a codeword of second information corresponding to the rth terminal is obtained according to a transmit rate and a transmit power for the codeword of the second information corresponding to the rth terminal, the transmit rate for the codeword of the first information corresponding to the rth terminal meets a first condition.