In the example shown in FIG. 1, DFI 0 for UE 0, DFI 1 for UE 1, DFI 2 for UE 2 and DFI M may be multiplexed using orthogonal cover code (OCC) or cyclic shift. DFI M may be scheduled by DFI 0/1/2 for transmission parameter adjustment of UE 0/1/2. According to an exemplary embodiment, first DFI such as DFI 0/1/2 may only carry HARQ A/N, while second DFI such as DFI M subsequent to the first DFI can carry updated transmission parameters and/or a set of change values of the transmission parameters. As shown in FIG. 1, UE x (x=0, 1 or 2) may receive both DFI x and DFI M at the same time or at different time. Then UE x can decode DFI x first. If DFI x indicates that DFI M is transmitted for UE x, this UE can further decode DFI M to derive the new transmission parameters. If DFI x indicates that DFI M is not transmitted for UE x, the UE can just discard the received signal for DFI M without decoding. Optionally, DFI M may be shared by DFI 0/1/2. This means that DFI 0/1/2 may be a UE dedicated signaling message while DFI M may be addressed to a group of UEs.
