If the beginning portion of a subframe has to be truncated (e.g., as shown in subframe (n+3) in FIG. 5), another alternative is for the eNB 104 to indicate the truncated beginning portion 506 of a given subframe with truncation (n+3) in the next subframe (n+4). For example, when the first few beginning symbols of subframe (n+3) shown in FIG. 5 are truncated, then instead of making the UE determine the starting symbol of control channel transmission 516 in subframe (n+3) via the blind decoding approaches described above, the eNB can signal the truncation information for subframe (n+3) using DCI of a PDCCH/EPDCCH transmitted in subframe (n+4) (not specifically shown). The DCI should have additional information indicating that the truncation information applies to the previous subframe (i.e., subframe n+3) and not the current subframe (n+4). This can be provided by a subframe indicator bit(s) in the DCI of subframe (n+4), or by using a configured cross-subframe RNTI. The DCI can also provide resource allocation information for the previous subframe (i.e., subframe n+3).

In current LTE systems, for receiving PDSCH transmissions for some transmission modes (e.g., TM 8, 9, or 10), the UE uses UE-specific demodulation reference signals (UERS) present in REs of the last two symbols of a subframe for LTE frame structure type 1 (FDD). However, for LTE operation on unlicensed carriers, in subframes where the last two or more symbols are truncated, these UERS will be unavailable to the UE, and utilizing only the remaining UERS in other non-truncated symbols will result in degraded channel estimation. Embodiments solve this problem by providing a more efficient alternative. That is, for LTE frame structure type 1 (FDD), for transmitting UE-specific reference signals for antenna ports 7, 8, 9 and 10: