A data transmission method comprising: determining, by a network side device, non-orthogonal multiple access basic transmission units allocated to User Equipments, UEs, each non-orthogonal multiple access basic transmission unit corresponding to a time-frequency resource, a pattern vector resource and a pilot resource, wherein the pattern vector resource corresponding to the non-orthogonal multiple access basic transmission unit comprises one column of a non-orthogonal multiple access, NOMA, pattern matrix as a basic unit; detecting, by the network side device, a pilot signal from each UE on the non-orthogonal multiple access basic transmission unit corresponding to the UE; and performing, by the network side device, data detection on the UE, which has transmitted the pilot signal, through the non-orthogonal multiple access basic transmission unit, in the case that the pilot signal has been detected, wherein the determining, by the network side device, the non-orthogonal multiple access basic transmission units allocated to the UEs comprises allocating, by the network side device, the non-orthogonal multiple access basic transmission units with pattern vectors having different diversities to the UEs in the NOMA pattern matrix in accordance with distances between the UEs and the network side device, wherein the non-orthogonal multiple access basic transmission unit with a pattern vector having a high diversity is allocated by the network side device to the UE at a large distance from the network side device; and wherein the diversity refers to the number of elements whose respective value is "1" in a Pattern Division Multiple Access, PDMA, pattern vector in the NOMA pattern matrix. determining, by a network side device, non-orthogonal multiple access basic transmission units allocated to User Equipments, UEs, each non-orthogonal multiple access basic transmission unit corresponding to a time-frequency resource, a pattern vector resource and a pilot resource, wherein the pattern vector resource corresponding to the non-orthogonal multiple access basic transmission unit comprises one column of a non-orthogonal multiple access, NOMA, pattern matrix as a basic unit; detecting, by the network side device, a pilot signal from each UE on the non-orthogonal multiple access basic transmission unit corresponding to the UE; and performing, by the network side device, data detection on the UE, which has transmitted the pilot signal, through the non-orthogonal multiple access basic transmission unit, in the case that the pilot signal has been detected, wherein the determining, by the network side device, the non-orthogonal multiple access basic transmission units allocated to the UEs comprises allocating, by the network side device, the non-orthogonal multiple access basic transmission units with pattern vectors having different diversities to the UEs in the NOMA pattern matrix in accordance with distances between the UEs and the network side device, wherein the non-orthogonal multiple access basic transmission unit with a pattern vector having a high diversity is allocated by the network side device to the UE at a large distance from the network side device; and wherein the diversity refers to the number of elements whose respective value is "1" in a Pattern Division Multiple Access, PDMA, pattern vector in the NOMA pattern matrix.