A user equipment (UE) is configured to communicate with a plurality of base stations in a wireless network. The UE includes a processor that receive a downlink grant scheduling a physical downlink shared channel (PDSCH) for the UE, the downlink grant being transmitted in a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (ePDCCH). The processor also receives UE-specific demodulation reference signals (UE-RS) provided for demodulation of the PDSCH, wherein the UE-RS are scrambled according to a scrambling sequence initialized with an initialization value cinit. The downlink grant includes a one-bit scrambling identifier (SCID) information field configured to indicate a pair of values comprising a scrambling identifier nSCID and a virtual cell ID Nv-IDcell out of two candidate pairs, the pair of values to be used for determining the initialization value cinit for the UE-RS.