A data transmission method, by a first UE is provided. The method includes detecting, on one or more carriers, a Physical Sidelink Control Channel (PSCCH) transmitted by a second UE, compensating, on each of the carriers, a Physical Sidelink Shared Channel's Demodulation Reference Signal Receiving Power (PSSCH-RSRP) of the second UE according to the detected PSCCH, determining, on each of the carriers, available candidate single-subframe resources according to the compensated PSSCH-RSRP, and transmitting the Physical Sidelink Shared Channel (PSSCH) using at least one of the available candidate single-subframe resources determined on all of the carriers.