Methods and apparatus are provided for wireless communication in which a downlink control information (DCI) is transmitted in a physical downlink control channel (PDCCH) in a first bandwidth part (BWP). A UE is responsible for determining a starting resource block (RB) for a data transmission allocated by the DCI based on a value of a frequency domain resource allocation field in the DCI, a reference RB, and a reference size of a second BWP. The data transmission can then be transmitted, in the case of, for example, PUSCH, by a UE or received, in the case of, for example, PDSCH.