6.4 Physical downlink shared channel
36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS
The physical downlink shared channel shall be processed and mapped to resource elements as described in clause 6.3 with the following additions and exceptions:
– In resource blocks in which UE-specific reference signals are not transmitted, the PDSCH shall be transmitted on the same set of antenna ports as the PBCH, which is one of 
, 
, or 
.
– In resource blocks in which UE-specific reference signals are transmitted, the PDSCH shall be transmitted on antenna port(s) 
,
,
, 
, 
, 
, 
, or the antenna ports listed in Table 6.3.4.4-1, where 
is the number of layers used for transmission of the PDSCH.
– If PDSCH is transmitted in MBSFN subframes as defined in TS 36.213 [4], the PDSCH shall be transmitted on one or several of antenna port(s) 
or on the antenna ports indicated in Table 6.3.4.4-1, where 
is the number of layers used for transmission of the PDSCH.
– PDSCH is not mapped to resource elements used for UE-specific reference signals associated with PDSCH
– In mapping to resource elements, the same positions of the cell-specifc reference shall be assumed for all antenna ports on which the PDSCH is transmitted and the positions of the cell-specific reference signals are given by clause 6.10.1.2 with the number of antenna ports and the frequency shift of the cell-specific reference signals derived as described in clause 6.10.1.2, unless indicated otherwise in clause 7.1.9 in TS 36.213 [4],
– if one set of parameters for cell-specific reference signal positions are provided by clause 7.1.9 in TS 36.213 [4], the values of these parameters are used for all antenna ports whereon the PDSCH is transmitted in the resource blocks indicated by the relevant DCI.
– if two sets of parameters for cell-specific reference signal positions are provided by clause 7.1.9 in TS 36.213 [4], the first set of parameters are used for the set of antenna ports associated with PDSCH codeword 
while the second set of parameters are used for the set of antenna ports associated with PDSCH codeword 
, according to codeword-to-layer mapping and layer-to-port mapping in Clause 6.3.3.2 and Clause 6.3.4.4, respectively.
– If the DCI associated with the PDSCH uses the C-RNTI or semi-persistent C-RNTI, PDSCH modulation symbols on the indicated antenna ports are not mapped to resource elements assumed by the UE to be used for transmission of:
– zero-power CSI reference signals, where the positions of the CSI reference signals assumed for each antenna port are given by clause 6.10.5.2. The configuration for zero power CSI reference signals is
– obtained as described in clause 6.10.5.2 and used for all antenna ports whereon the PDSCH is transmitted, unless indicated otherwise in clause 7.1.9 in TS 36.213 [4]
– if one set of parameters for zero power CSI reference signal configuration is provided by clause 7.1.9 in TS 36.213 [4], the values of these parameters are used for all antenna ports on which the PDSCH is transmitted in the resource blocks indicated by the corresponding DCI scheduling the PDSCH, and
– if two sets of parameters for zero power CSI reference signal configuration are provided by clause 7.1.9 in TS 36.213 [4], the first set of parameters are used for the set of antenna ports associated with PDSCH codeword 
while the second set of parameters are used for the set of antenna ports associated with PDSCH codeword 
, according to codeword-to-layer mapping and layer-to-port mapping in Clause 6.3.3.2 and Clause 6.3.4.4, respectively.
– obtained by higher-layer configuration of up to five reserved CSI-RS resources as part of the discovery signal configuration following the procedure for zero-power CSI-RS in clause 6.10.5.2.
– non-zero-power CSI reference signals for CSI reporting, except for non-zero power CSI reference signals configured by csi-RS-ConfigNZP-ApList, where the positions of the non-zero-power CSI reference signals for CSI reporting are given by clause 6.10.5.2. The configuration for non-zero power CSI reference signals is obtained as described in clause 6.10.5.2.
– PDSCH is not mapped to any physical resource-block pair(s) carrying an EPDCCH associated with the PDSCH.
– PDSCH with subframe duration on antenna port 7, 8, 9, 10, 11, 12, 13 or 14 is not mapped to any physical resource-block pair(s) carrying PBCH or synchronization signals.
– Frame structure type 1, PDSCH on antenna port 5 is not mapped to any physical resource-block pair(s) carrying PBCH or synchronization signals.
– Frame structure type 2, PDSCH on antenna port 5 is not mapped to any physical resource-block pair(s) carrying PBCH.
– For frame structure type 1 and 2, the index 
in the first slot in a subframe fulfils 
where 
is given by clause 7.1.6.4 of TS 36.213 [4].
– For frame structure type 3,
– if the higher layer parameter subframeStartPosition indicates ‘s07’ and the downlink transmission starts in the second slot of a subframe
– the index 
in the second slot in a subframe fulfils 
where 
is given by clause 7.1.6.4 of TS 36.213 [4],
– otherwise
– the index 
in the first slot in a subframe fulfils 
where 
is given by clause 7.1.6.4 of TS 36.213 [4],
– In mapping to resource elements, if the DCI associated with the PDSCH uses the C-RNTI or semi-persistent C-RNTI, and transmit diversity according to clause 6.3.4.3 is used, and if the higher-layer parameter semiOpenLoop is not set and if the DCI associated with the PDSCH is not of format 7, resource elements in an OFDM symbol assumed by the UE to contain CSI-RS shall be used in the mapping if and only if all of the following criteria are fulfilled:
– there is an even number of resource elements for the OFDM symbol in each resource block assigned for transmission, and
– the complex-valued symbols 
and 
, where 
is an even number, can be mapped to resource elements 
and 
in the same OFDM symbol with 
.
– In mapping to resource elements, if the DCI associated with the PDSCH uses C-RNTI or semi-persistent C-RNTI and if the higher-layer parameter semiOpenLoop is set for subframe PDSCH or the higher-layer parameter semiOpenLoop-STTI is set for slot/subslot PDSCH or if the DCI associated with the PDSCH is of format 7 and transmit diversity according to clause 6.3.4.3 is used, a pair of resource elements 
, 
shall be used in the mapping if and only if
– the complex-valued symbols 
and 
can be mapped to resource elements 
and 
in the same OFDM symbol and the same PRB with 
, where 
is an even number and 
starts from 0 at the lowest subcarrier of the PRB.
6.4.1 Physical downlink shared channel for BL/CE UEs
For BL/CE UEs, the following additions and exceptions hold in addition to those in clause 6.4:
– The maximum number of allocatable PRBs for PDSCH is restricted as follows:
– If the PDSCH is associated with C-RNTI or SPS C-RNTI and the higher layer parameter ce-pdsch-maxBandwidth-config is set,
– if the higher layer parameter ce-pdsch-maxBandwidth-config is set to 20 MHz, the maximum number of allocatable PRBs for PDSCH is 96 PRBs restricted to the narrowbands defined in clause 6.2.7;
– if the higher layer parameter ce-pdsch-maxBandwidth-config is set to 5 MHz, the maximum number of allocatable PRBs for PDSCH is 24 PRBs restricted to no more than four of the narrowbands defined in clause 6.2.7.
– If the PDSCH is associated with G-RNTI and the higher layer parameter pdsch-MaxBandwidth-SC-MTCH is set to 24 PRBs, the maximum number of allocatable PRBs for PDSCH is 24 PRBs restricted to no more than four of the narrowbands defined in clause 6.2.7.
– For all other cases, the maximum number of allocatable PRBs for PDSCH is 6 PRBs restricted to one of the narrowbands defined in clause 6.2.7.
– Resource elements occupied by CSI reference signals shall be counted in the PDSCH mapping but not used for transmission of the PDSCH.
– Resource elements belonging to synchronization signals, the core part of PBCH, PBCH repetitions, or resource elements reserved for reference signals in the mapping operation of PBCH but not used for transmission of reference signals, shall be counted in the PDSCH mapping but not used for transmission of the PDSCH.
– PRB pairs occupied by RSS shall be counted in the PDSCH mapping but not used for transmission of the PDSCH.
– For BL/CE UEs in CEModeB configured in transmission mode 9, in MBSFN subframe(s), resource elements that correspond to the positions of cell-specific reference signals as in subframe #0 shall not be counted in the PDSCH mapping and not used for transmission of the PDSCH.
– Resource elements belonging to PRBs in which PRS is transmitted (including PRS muted subframes) shall be counted in the PDSCH mapping but not used for transmission of the PDSCH.
– If the higher layer parameter ce-punctured-subcarriers-DL is configured, and the DCI associated with the PDSCH uses C-RNTI or SPS C-RNTI, and transmit diversity according to clause 6.3.4.3 is used,
– In the mapping to resource elements, when the complex-valued symbols 
and 
, where 
is an even number, are mapped to resource elements 
and 
in the same OFDM symbol with 
, then if ce-punctured-subcarriers-DL indicates that any of 
and 
shall be counted but not used for transmission, the UE shall assume that both 
and 
are counted but not used for transmission.
– If PDSCH transmission in the LTE control region is configured by higher layer parameter transmissionInControlChRegion, after the initial mapping of the PDSCH to resource elements starting from in the first slot to the last OFDM symbol available for downlink transmission in the subframe has been performed, the mapping shall continue with resource elements not reserved for cell-specific reference signals in increasing order of first the index over the assigned physical resource blocks and then the index starting from in the first slot to in the first slot, where is given by clause 7.1.6.4 of TS 36.213 [4].
For BL/CE UEs, if the PDSCH is not carrying SIB1-BR the PRB resources for PDSCH transmission in the first subframe are obtained from the DCI as described in clauses 5.3.3.1.12, 5.3.3.1.13, and 5.5.1.3.14 in [3], or provided by higher layers. Each of the PDSCH codewords is transmitted with 
repetitions, where is the number of transport blocks defined in clause 7.1.11 of TS 36.213 [4]. The PDSCH transmission spans consecutive subframes, including subframes that are not BL/CE DL subframes where the PDSCH transmission is postponed.
– If downlink resource reservation is enabled for the UE as specified in [9], and the Resource reservation field in the DCI is set to 1, then in case of PDSCH transmission associated with C-RNTI or SPS C-RNTI using UE-specific MPDCCH search space including PDSCH transmission without a corresponding MPDCCH,
– In a subframe that is fully reserved as defined in clause 7.1 in [4], the PDSCH transmission is postponed until the next BL/CE downlink subframe that is not fully reserved.
– In a subframe that is partially reserved, the reserved resource elements shall be counted in the PDSCH mapping but not used for transmission of the PDSCH.
– If frequency hopping is not enabled for PDSCH, all PDSCH repetitions are located at the same PRB resources, and
– if frequency hopping is enabled for PDSCH, the PDSCH shall be transmitted in subframe 
within the 
consecutive downlink subframes using the PRB resources of the narrowband 
with the same RIV as that of narrowband 
. The narrowband 
is defined as
where 
is the absolute subframe number of the first downlink subframe intended for PDSCH and 
, 
and 
are cell-specific higher-layer parameters. For PDSCH carrying SI other than SIB1-BR and for PDSCH associated with P-RNTI, if interval-DlHoppingConfigCommonModeB is signalled in SIB1-BR, then the frequency hopping granularity 
is set to interval-DlHoppingConfigCommonModeB; otherwise, 
is set to interval-DlHoppingConfigCommonModeA signalled in SIB1-BR.
For BL/CE UE in CEModeA, frequency hopping of PDSCH associated with C-RNTI or SPS C-RNTI is enabled when higher layer parameter mpdcch-pdsch-HoppingConfig is set and the frequency hopping flag in DCI format 6-1A indicates frequency hopping, otherwise, frequency hopping of is not enabled. For BL/CE UE in CEModeB, frequency hopping of PDSCH associated with C-RNTI or SPS C-RNTI is enabled when higher layer parameter mpdcch-pdsch-HoppingConfig is set, otherwise, frequency hopping of is not enabled.
The UE shall not expect PDSCH in subframe 
if it is not a BL/CE DL subframe.
For BL/CE UEs, if the PDSCH carries SIB1-BR, the PDSCH transmission is repeated periodically in every period of 8 radio frames, where a period starts with a radio frame with 
where 
is the system frame number. The PDSCH is transmitted 
times in each period of 8 frames, Let 
be the set of narrowbands, excluding narrowbands overlapping with the 72 center subcarriers for 
, and ordered in increasing order of narrowband index. The PDSCH transmission cycles through the set 
of narrowbands in increasing order of 
, starting with 
for the first subframe, according to
where 
is the number of narrowbands in the set 
.
The set of frames and subframes used for SIB1-BR transmission in each period are given by Tables 6.4.1-1 and 6.4.1-2.
Table 6.4.1-1: The set of frames and subframes for SIB1-BR for 
.
|
|
|
Frame structure type 1 |
Frame structure type 2 |
||
|
|
|
|
|
||
|
4 |
0 |
0 |
4 |
1 |
5 |
|
1 |
1 |
4 |
1 |
5 |
|
Table 6.4.1-2: The set of frames and subframes for SIB1-BR for 
.
|
|
|
Frame structure type 1 |
Frame structure type 2 |
||
|
|
|
|
|
||
|
4 |
0 |
0 |
4 |
1 |
5 |
|
1 |
1 |
4 |
1 |
0 |
|
|
8 |
0 |
0, 1 |
4 |
0, 1 |
5 |
|
1 |
0, 1 |
9 |
0, 1 |
0 |
|
|
16 |
0 |
0, 1 |
4, 9 |
0, 1 |
0, 5 |
|
1 |
0, 1 |
0, 9 |
0, 1 |
0, 5 |
|
BL/CE UEs may assume the same precoding matrix being used for a PRB across a block of 
consecutive subframes when UE-specific reference signals are transmitted together with the PDSCH, where the subframe number of the first subframe in each block of 
consecutive subframes, denoted as 
, satisfies 
.
For PDSCH transmission associated with SI-RNTI or P-RNTI to BL/CE UEs, frequency hopping of the PDSCH is enabled when higher layer parameter si-HoppingConfigCommon is set.
For PDSCH transmission associated with PUR-RNTI to BL/CE UEs using UE-specific MPDCCH search space, frequency hopping of the PDSCH is enabled when higher layer parameter pur-PDSCH-FreqHopping is set.
For PDSCH transmission associated with RA-RNTI or temporary C-RNTI to BL/CE UEs, frequency hopping of the PDSCH is enabled when higher layer parameter rar-HoppingConfig is set. Further
– if PRACH CE level 0 or 1 is used for the last PRACH attempt, 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeA;
– if PRACH CE level 2 or 3 is used for the last PRACH attempt, 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeB.
For PDSCH transmission associated with SC-RNTI to BL/CE UEs, frequency hopping of the PDSCH is enabled when higher layer parameter mpdcch-pdsch-HoppingConfig-SC-MCCH is set. Further
– if mpdcch-pdsch-HoppingConfig-SC-MCCH is set to CEModeA, 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeA;
– if mpdcch-pdsch-HoppingConfig-SC-MCCH is set to CEModeB, 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeB.
For PDSCH transmission associated with G-RNTI to BL/CE UEs,
– if the higher layer parameter mpdcch-pdsch-CEmodeConfig-SC-MTCH is set to CEModeA,
– if the higher layer parameter mpdcch-pdsch-HoppingConfig-SC-MTCH is set and the frequency hopping flag in DCI format 6-1A indicates frequency hopping, then frequency hopping of the PDSCH is enabled and 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeA, otherwise frequency hopping is not enabled;
– if the higher layer parameter mpdcch-pdsch-CEmodeConfig-SC-MTCH is set to CEModeB,
– if the higher layer parameter mpdcch-pdsch-HoppingConfig-SC-MTCH is set, then frequency hopping of the PDSCH is enabled and 
is set to the higher layer parameter interval-DlHoppingConfigCommonModeB, otherwise frequency hopping is not enabled.
6.4.2 Slot/subslot-based physical downlink shared channel
For slot or subslot-based PDSCH, in this specification referred to as slot-PDSCH and subslot-PDSCH respectively, the following additions and exceptions hold in addition to those in clause 6.4:
– PDSCH is not mapped to resource elements of SCCEs used by the associated SPDCCH, or resource elements used for UE-specific reference signals associated with SPDCCH
– In case of slot-PDSCH:
– the mapping to resource elements 
on antenna port 
not reserved for other purposes shall be in increasing order of first the index 
over the assigned physical resource blocks and then the index
, for the slot of the assigned physical resources in the subframe, and
– in case of UE-specific reference signals, the PDSCH is not mapped to any physical resource blocks carrying PBCH.
– In case of subslot-PDSCH:
– the mapping to resource elements 
on antenna port 
not reserved for other purposes shall be in increasing order of first the index 
over the assigned physical resource blocks and then the index
, starting from 
given in Table 6.4.2-1. The starting value 
and the value range of 
depends on the number of symbols used for PDCCH and the subslot number in the subframe, according to Table 6.4.2-1, and
– in case of UE-specific reference signals,
– the PDSCH is not mapped to any physical resource blocks in frequency domain carrying PBCH or synchronization signals for the OFDM symbols of the given subslot.
– and in case the DCI associated with the subslot-PDSCH indicates the absence of the UE-specific reference signals (see DMRS position indicator field in TS 36.212 [3]), the PDSCH is not mapped to any physical resource blocks in frequency domain that carried PBCH or synchronization signals for the OFDM symbols of the previous subslot.
Table 6.4.2-1: Starting value of index 
, i.e. 
, for subslot PDSCH
|
Number of symbols used for PDCCH |
Downlink subslot index |
|||||
|
#0 |
#1 |
#2 |
#3 |
#4 |
#5 |
|
|
1 |
1 |
3 |
5 |
0 |
2 |
4 |
|
2 |
– |
2 |
5 |
0 |
2 |
4 |
|
3 |
– |
3 |
5 |
0 |
2 |
4 |
– For PDSCH associated with UE-specific reference signals,
– the PDSCH shall only be mapped to physical resource blocks in frequency domain assigned for PDSCH transmission where the assignment maps to both physical resource blocks of a PRG.
– the subslot-PDSCH shall not be mapped to the physical resource blocks of a PRG in case the resource elements of the associated SPDCCH are mapped to those physical resource blocks.
– In addition, the following additions and exceptions related to L1 signaling and/or higher layer configuration controlling rate-matching around SPDCCH resources hold:
– PDSCH is not mapped to resource elements belonging to a SPDCCH resource set configured with higher layer parameter rateMatchingMode indicating ‘m2’ if either this SPDCCH resource set is not configured with higher layer parameter spdcch-L1-ReuseIndication or it is configured with higher layer parameter spdcch-L1-ReuseIndication ‘n1’ or ‘n2’ indicating ‘0’ for the SPDCCH resource set.
– PDSCH is not mapped to resource elements belonging to a SPDCCH resource set configured with higher layer parameter rateMatchingMode indicating ‘m3’ if the SPDCCH associated with PDSCH is found in this SPDCCH resource set and if either this SPDCCH resource set is not configured with higher layer parameter spdcch-L1-ReuseIndication or it is configured with higher layer parameter spdcch-L1-ReuseIndication ‘n1’ or ‘n2’ indicating ‘0’ for the SPDCCH resource set. If the SPDCCH associated with PDSCH is found on a candidate belonging to two SPDCCH resource sets, the SPDCCH is assumed to be found in both SPDCCH resource sets.
– PDSCH is not mapped to resource elements belonging to a SPDCCH resource set configured with higher layer parameter rateMatchingMode indicating ‘m4’ if the SPDCCH associated with PDSCH is not found in this SPDCCH resource set and if either this SPDCCH resource set is not configured with higher layer parameter spdcch-L1-ReuseIndication or it is configured with higher layer parameter spdcch-L1-ReuseIndication ‘n1’ or ‘n2’ indicating ‘0’ for the SPDCCH resource set.
– PDSCH is not mapped to resource elements belonging to a SPDCCH resource set configured with higher layer parameter spdcch-L1-ReuseIndication ‘n0’ if the bit of the Used/Unused SPDCCH resource indication field corresponding to this SPDCCH resource set in the DCI format 7 associated with PDSCH is set to 1.
– PDSCH is not mapped to resource elements belonging to SCCE#0 to SCCE#
of a SPDCCH resource set configured with higher layer parameter spdcch-L1-ReuseIndication ‘n1’ or ‘n2’ indicating ‘2’ for the SPDCCH resource set if the most significant bit of the Used/Unused SPDCCH resource indication field in the DCI format 7 associated with PDSCH is set to 1.
– PDSCH is not mapped to resource elements belonging to SCCE#
to SCCE#
of a SPDCCH resource set configured with higher layer parameter spdcch-L1-ReuseIndication ‘n1’ or ‘n2’ indicating ‘2’ for the SPDCCH resource set if the least significant bit of the Used/Unused SPDCCH resource indication field in the DCI format 7 associated with PDSCH is set to 1.
– It should be noted that not mapping PDSCH to resource elements belonging to a SPDCCH resource set holds irrespective of other indications (spdcch-L1-ReuseIndication or rateMatchingMode) associated with other SPDCCH resource sets (if configured).
– For a UE with the higher-layer parameter blindSlotSubslotPDSCH-Repetitions set to TRUE and PDSCH associated with a downlink assignment sent on PDCCH/SPDCCH with DCI format 7 indicating transmissions, the rate-matching around SPDCCH resources if applicable for PDSCH in the valid slots/subslots following the slot/subslot containing the downlink assignment follows
– the rate-matching around SPDCCH resources of the PDSCH in the slot/subslot containing the downlink assignment, if the DCI format 7 indicating transmissions is received on SPDCCH.
– the rate-matching around SPDCCH resources of the PDSCH in the SPDCCH resource set according to rateMatchingMode indicating ‘m2’, if configured by higher layers, if the DCI format 7 indicating 
transmissions is received on PDCCH. For other configurations of rateMatchingMode, no rate-matching around SPDCCH resources for PDSCH in the valid slots/subslots following the PDCCH with DCI format 7 indicating PDSCH transmissions is applied..