Section: 6.8.5 Mapping to resource elements
Content: The mapping to resource elements is defined by operations on quadruplets of complex-valued symbols. Let denote symbol quadruplet for antenna port. The block of quadruplets , where , shall be permuted resulting in . The permutation shall be according to the sub-block interleaver in clause 5.1.4.2.1 of TS 36.212[ Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding ]  [3] with the following exceptions: - the input and output to the interleaver is defined by symbol quadruplets instead of bits - interleaving is performed on symbol quadruplets instead of bits by substituting the terms "bit", "bits" and "bit sequence" in clause 5.1.4.2.1 of TS 36.212[ Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding ]  [3] by "symbol quadruplet", "symbol quadruplets" and "symbol-quadruplet sequence", respectively <NULL> elements at the output of the interleaver in TS 36.212[ Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding ]  [3] shall be removed when forming . Note that the removal of <NULL> elements does not affect any <NIL> elements inserted in clause 6.8.2. The block of quadruplets shall be cyclically shifted, resulting in where. Mapping of the block of quadruplets is defined in terms of resource-element groups, specified in clause 6.2.4, according to steps 1–10 below: 1) Initialize (resource-element group number) 2) Initialize 3) Initialize 4) If the resource element represents a resource-element group and the resource-element group is not assigned to PCFICH or PHICH then perform step 5 and 6, else go to step 7 5) Map symbol-quadruplet to the resource-element group represented by for each antenna port 6) Increase by 1 7) Increase by 1 8) Repeat from step 4 if , where corresponds to the number of OFDM symbols used for PDCCH transmission. The quantity is obtained from - the sequence transmitted on the PCFICH, or - the higher-layer parameter cfi-SubframeMBSFN-r15 for DCI formats other than DCI format 7 in a MBSFN subframe, or - the higher-layer parameter cfi-SlotSubslotMBSFN-r15 for DCI format 7 in a MBSFN subframe, or - the higher-layer parameter cfi-SubframeNonMBSFN-r15 for DCI formats other than DCI format 7 in a non-MBSFN subframe, or - the higher-layer parameter cfi-SlotSubslotNonMBSFN-r15 for DCI format 7 in a non-MBSFN subframe, or - the higher-layer parameter cfi-PatternSubframe-r15 for DCI formats other than DCI format 7 in one subframe for frame structure 2, or - the higher-layer parameter cfi-PatternSlotSubslot-r15 for DCI formats 7 in one subframe for frame structure 2. 9) Increase by 1 10) Repeat from step 3 if PDCCHs shall not be transmitted in MBSFN subframes with zero-size non-MBSFN region.