A method of efficient wideband operation for intra-band non-contiguous spectrum using extending bandwidth part (BWP) configuration is proposed. The BWP definition is extended to cluster BWPs to aggregate distributed spectrum blocks within a frequency range (e.g., 200 MHz) by single carrier operation and facilitate UE to filter out the transmission of unknown RAT between any two of the distributed spectrum blocks. In addition, the cluster BWP configuration enables dynamic aggregation of the number and location of the distributed spectrum blocks based on LBT results in unlicensed spectrum. Specifically, the BWP definition is extended to a group of one or multiple radio resource clusters, each of which contains a set of contiguous PRBs in frequency domain within the associated carrier.