Section: 6.10.3A.2 Mapping to resource elements
Content: For the antenna port in a physical resource block assigned for the associated EPDCCH/MPDCCH, a part of the reference signal sequence shall be mapped to complex-valued modulation symbols in a subframe according to Normal cyclic prefix: where The sequence is given by Table 6.10.3A.2-1. Table 6.10.3A.2-1: The sequence for normal cyclic prefix Extended cyclic prefix: where The sequence is given by Table 6.10.3A.2-2. Table 6.10.3A.2-2: The sequence for extended cyclic prefix For extended cyclic prefix, demodulation reference signals are not supported on antenna ports 109 to 110. For the antenna port in a physical resource block assigned for the SPDCCH, a part of the reference signal sequence shall be mapped to complex-valued modulation symbols in a subframe according to the procedure used for UE-specific reference signals associated with subslot-PDSCH on antenna port described in clause 6.10.3.2 with the following amendments: - for slot-SPDCCH, , - for slot-SPDCCH in MBSFN subframes, the procedure used for the baseline pattern of UE-specific reference signals associated with subslot-PDSCH is applied - for slot-SPDCCH in normal subframes, the procedure used for the shifted pattern of UE-specific reference signals associated with subslot-PDSCH depending on the cell-specific frequency shift is applied. Resource elements used for transmission of demodulation reference signals to one UE on any of the antenna ports in the set , where or shall - not be used for transmission of EPDCCH/MPDCCH on any antenna port in the same slot, and - not be used for demodulation reference signals to the same UE on any antenna port other than those in in the same slot. Replacing antenna port numbers 7 – 10 by 107 – 110 in Figure 6.10.3.2-3 provides an illustration of the resource elements used for demodulation reference signals associated with EPDCCH/MPDCCH for normal cyclic prefix. Replacing antenna port numbers 7 – 8 by 107 – 108 in Figure 6.10.3.2-4 provides an illustration of the resource elements used for demodulation reference signals associated with EPDCCH/MPDCCH for extended cyclic prefix. For frame structure type 3, for EPDCCH in a subframe with the same duration as the DwPTS duration of a special subframe configuration, the mapping of the demodulation reference signals to the resource elements is the same as that for the corresponding special subframe configuration. For BL/CE UEs, if downlink resource reservation is enabled for the UE as specified in [9], then in case of MPDCCH transmission associated with C-RNTI or SPS C-RNTI using UE-specific MPDCCH search space, - If all OFDM symbols in a PRB are reserved, the demodulation reference signal transmission in that PRB is dropped.