Patent ID: 8842622

Claim:
A method implementable in a wireless transmit/receive unit (WTRU) in communication with a plurality of transmission (Tx) points, comprising: receiving radio resource control (RRC) signaling including first and second parameters of a demodulation reference signals (DM-RS) configuration associated with the plurality of Tx points; receiving, on a downlink control channel associated with a forthcoming coordinated downlink transmission to the WTRU, downlink control information including an indication of an antenna port index, scrambling identity and number of layers; determining the scrambling identity based on the indication and on whether a single codeword of a plurality of codewords is enabled or multiple codewords of the plurality of codewords are enabled; on condition that the scrambling identity is determined to be a first value: selecting the first parameter; and generating a first DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the first parameter and the first value of the scrambling identity as inputs for initializing the first DM-RS sequence; and on condition that the scrambling identity is determined to be a second value: selecting the second parameter; and generating a second DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the second parameter and the second value of the scrambling identity as inputs for initializing the second DM-RS sequence.