A wireless transmit receive unit (WTRU) is configured to receive a reference signal of a first type. The first type is other than a demodulation reference signal (DM-RS). Reference signals of the first type are received in resource elements other than resource elements used for a primary synchronization signal or a secondary synchronization signal. The WTRU is configured to receive a radio resource control message indicating a subframe position in which the reference signal of the first type is transmitted and a periodicity of a transmission of the reference signal of the first type.