A signal transmission method, comprising: separately performing at a transmit end phase rotation on M pieces of modulated data to obtain M pieces of phase-rotated data, wherein a phase factor used for performing phase rotation on the M pieces of modulated data is determined based on M, which is the length of the modulated data; determining at the transmit end time domain data based on the M pieces of phase-rotated data; and sending the time domain data to a receive end; and wherein the separately performing phase rotation on M pieces of modulated data comprises: performing phase rotation on modulated data with an index m in the M pieces of modulated data based on a phase factor corresponding to the modulated data with the index m, wherein m traverses 0 to M-1, and m is an integer, and based on a symbol index of a symbol corresponding to the M pieces of modulated data, wherein the symbol index of the symbol in which the M pieces of modulated data are located is l.; and the phase factor corresponding to the modulated data with the index m is: e j × φ m = e j 2 π × m × ⌊ M × A / h ⌋ / M × e jπ × l / 2, wherein e j × φ m is the phase factor corresponding to the modulated data with the index m, and A and h are integers, and wherein values of A and h are preconfigured at the transmit end, or values of A and h are obtained at the transmit end according to a predefined rule, or values of A and h are notified by the receive end to the transmit end by using signaling. separately performing at a transmit end phase rotation on M pieces of modulated data to obtain M pieces of phase-rotated data, wherein a phase factor used for performing phase rotation on the M pieces of modulated data is determined based on M, which is the length of the modulated data; determining at the transmit end time domain data based on the M pieces of phase-rotated data; and sending the time domain data to a receive end; and wherein the separately performing phase rotation on M pieces of modulated data comprises: performing phase rotation on modulated data with an index m in the M pieces of modulated data based on a phase factor corresponding to the modulated data with the index m, wherein m traverses 0 to M-1, and m is an integer, and based on a symbol index of a symbol corresponding to the M pieces of modulated data, wherein the symbol index of the symbol in which the M pieces of modulated data are located is l.; and the phase factor corresponding to the modulated data with the index m is: e j × φ m = e j 2 π × m × ⌊ M × A / h ⌋ / M × e jπ × l / 2, wherein e j × φ m is the phase factor corresponding to the modulated data with the index m, and A and h are integers, and wherein values of A and h are preconfigured at the transmit end, or values of A and h are obtained at the transmit end according to a predefined rule, or values of A and h are notified by the receive end to the transmit end by using signaling. performing phase rotation on modulated data with an index m in the M pieces of modulated data based on a phase factor corresponding to the modulated data with the index m, wherein m traverses 0 to M-1, and m is an integer, and based on a symbol index of a symbol corresponding to the M pieces of modulated data, wherein the symbol index of the symbol in which the M pieces of modulated data are located is l.; and the phase factor corresponding to the modulated data with the index m is: e j × φ m = e j 2 π × m × ⌊ M × A / h ⌋ / M × e jπ × l / 2, wherein e j × φ m is the phase factor corresponding to the modulated data with the index m, and A and h are integers, and wherein values of A and h are preconfigured at the transmit end, or values of A and h are obtained at the transmit end according to a predefined rule, or values of A and h are notified by the receive end to the transmit end by using signaling.