A UE determines a first DCCH resource candidate in a first CORESET on a carrier, the first DCCH resource candidate including a first set of RBs. The UE also determines a first sequence of DMRSs that are mapped, starting at a reference point, to RBs in a predetermined range within the carrier in a frequency domain, the predetermined range containing the first DCCH resource candidate in the frequency domain. The UE further determines a first reference location of the first set of RBs. The UE determines, based on the first reference location, a first set of DMRSs from the first sequence of DMRSs, the first set of DMRSs being mapped to the first set of RBs. The UE obtains a channel estimation based on the first set of DMRSs; and The UE performs blind decoding of the first DCCH resource candidate based on the channel estimation.