Respective demodulation reference signals (DM RS) of a user bandwidth can be cyclically shifted with respect to each other. An uplink scheduling grant may include an index for a DM RS resource having a cyclic shift and an orthogonal cover code or interleaved frequency division multiple comb. A usage orthogonal cover or interleaved frequency division multiple comb may be configured using radio resource control message and may optionally be tied statically into DM RS resources. At least some of respective demodulation reference signals of the at least two user bandwidths may be mutually orthogonal.