A data processing method performed by a Universal Mobile Telecommunications System Frequency Division Duplexing (UMTS-FDD) device includes at least the following steps: receiving a control frame from a dedicated physical control channel (DPCCH) and a data frame from a dedicated physical data channel (DPDCH), wherein the control frame includes n slots, and each slot thereof includes at least a portion of a transport format combination indicator (TFCI) codeword, wherein n is a positive integer, and the TFCI codeword is encoded from TFCI content for indicating a transport format combination of the data frame; and when m of the n slots are received, starting to decode the data frame according to the m slots, wherein m is a positive integer and less than n.