9.1.6 SPDCCH assignment procedure

36.2133GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical layer proceduresRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

If the UE is configured with shortTTI, and SPDCCH is monitored in a slot, the term ‘slot/subslot’ refers to a slot in this clause.

If the UE is configured with shortTTI, and SPDCCH is monitored in a subslot, the term ‘slot/subslot’ refers to a subslot in this clause.

A UE configured with shortTTI is not expected to be configured with MBSFN subframe with zero-size non-MBSFN region.

For each serving cell, higher layer signalling can configure a UE with

– one or two SPDCCH-PRB-sets for SPDCCH monitoring in a slot/subslot of a non-MBSFN subframe, and

– one or two SPDCCH-PRB-sets for SPDCCH monitoring in a slot/subslot of an MBSFN subframe.

The PRBs corresponding to a SPDCCH-PRB-set are indicated by higher layers as described in Clause 9.1.6.2. Each SPDCCH-PRB-set consists of a set of SCCEs numbered from 0 to where is the number of SCCEs in SPDCCH-PRB-set in a subframe. Each SPDCCH-PRB-set can be configured for either localized SPDCCH transmission or distributed SPDCCH transmission.

The UE shall monitor a set of SPDCCH candidates on one or more activated serving cells as configured by higher layer signalling for control information, where monitoring implies attempting to decode each of the SPDCCHs in the set according to the monitored DCI formats.

A UE is not required to monitor CRS-based SPDCCH in an MBSFN subframe.

A UE is not required to monitor CRS-based SPDCCH and DMRS-based SPDCCH in a slot/subslot if the UE does not support differentRSType.

A UE is not expected to receive DMRS-based SPDCCH scheduling PDSCH in slots/subslots where the UE is configured with DL transmission modes 1-4, 6.

The UE is not expected to be configured to monitor SPDCCH with carrier indicator field in a given serving cell.

The UE is not expected to monitor

– SPDCCH in the first subslot of a subframe

– SPDCCH in the first slot of a subframe if higher layer parameters dl-STTI-Length is set to ‘slot’.

For 4 port CRS-based SPDCCH, a UE is not required to receive an SREG belonging to multiple PDCCH candidates if any resource element in that SREG corresponds to different antenna ports for those multiple PDCCH candidates, where the precoding sub-matrix is described in the precoding operation from clause 6.3.4.3 of 3GPP TS 36.211 [3].

The set of SPDCCH candidates to monitor are defined in terms of SPDCCH UE-specific search spaces. An SPDCCH UE-specific search space or slot/subslot number k at aggregation level is defined by a set of SPDCCH candidates.

For a CRS-based SPDCCH-PRB-set or a DMRS-based SPDCCH-PRB-set configured with localized SPDCCH transmission in slot/subslot number , the SCCEs corresponding to SPDCCH candidate of the search space at aggregation level are given by

For a DMRS-based SPDCCH-PRB-set configured with distributed SPDCCH transmission in slot/subslot number k, the SCCEs corresponding to SPDCCH candidate of the search space are given by

where

is determined by higher layer parameter al- StartingPointSPDCCH,

is the number of SPDCCH candidates, determined by higher layer parameter dci7-CandidateSetsPerAL-SPDCCH-r15, to monitor among all the configured DCI formats for an aggregation level in SPDCCH-PRB-set in slot/subslot number ,.

For SPDCCH-PRB-set , and k belonging to the set of subslots indicated by higher layer parameter subslotApplicability-r15, is given by the first value of higher layer parameter dci7-CandidateSetsPerAL-SPDCCH-r15 corresponding to aggregation level , otherwise, is given by the second value of higher layer parameter dci7-CandidateSetsPerAL-SPDCCH-r15 corresponding to aggregation level .

The UE is not required to receive DMRS-based SPDCCH on resource blocks of a PRG overlapping with PBCH or primary or secondary synchronization signals in a slot/subslot.

A UE is not expected to be configured to monitor more than

– 6 SPDCCH candidates on a service cell in a subslot if the higher layer parameter dl-STTI-Length is set to ‘subslot’

– 12 SPDCCH candidates on a serving cell in a slot if the higher layer parameter dl-STTI-Length is set to ‘slot’.

A UE is not expected to monitor SPDCCH candidates over more than

– 16 SCCEs on a serving cell in a subslot if the higher layer parameter dl-STTI-Length is set to ‘subslot’

– 32 SCCEs on a serving cell in a slot if the higher layer parameter dl-STTI-Length is set to ‘slot’

A UE is not expected to monitor more than numberOfBlindeDecodesUSS DCI blind decodes on PDCCH/EPDCCH and SPDCCH UE-specific search space(s) in a subframe if the UE indicated capability numberOfBlindeDecodesUSS .

9.1.6.1 Resource mapping parameters for SPDCCH

For a given serving cell, if the UE is configured via higher layer signalling to monitor SPDCCH, for each SPDCCH-PRB-set, for

– CRS-based SPDCCH, the UE shall use the parameter set indicated by the higher layer parameter sPDCCH-NoOfSymbols to determine the SPDCCH symbols starting from the first OFDM symbol of the slot/subslot.

9.1.6.2 PRB-pair indication for SPDCCH

For a given serving cell, for each CRS-based SPDCCH-PRB set , the UE is configured with a higher layer parameter resourceBlockAssignment indicating a combinatorial index corresponding to the PRB index , () and given by equation , where is the number of PRB-pairs associated with the downlink bandwidth, is the number of PRB-pairs constituting SPDCCH-PRB-set, and is configured by the higher layer parameter numberRB-InFreq-domain and is the extended binomial coefficient, resulting in unique label .

For a given serving cell, for each DMRS-based SPDCCH-PRB set , the UE is configured with a higher layer parameter resourceBlockAssignment indicating a combinatorial index corresponding to the PRB indices , and , () and given by equation , where is the number of PRB-pairs associated with the downlink bandwidth, is the number of PRB-pairs constituting SPDCCH-PRB-set, and is configured by the higher layer parameter numberRB-InFreq-domain and is the extended binomial coefficient, resulting in unique label .

9.1.6.3 Physical Resource Block (PRB) bundling for DMRS-based SPDCCH

For an SPDCCH-PRB-set with DMRS-based SPDCCH candidates, precoding granularity is 2 resource blocks in frequency domain. Precoding Resource block Groups (PRGs) of size 2 partition the system bandwidth and each PRG consists of consecutive PRBs. The UE is expected to receive UE-specific reference signal corresponding to a DMRS-based SPDCCH candidate over both resource blocks of a PRG. If then, no DMRS-based SPDCCH candidate is mapped to the last resource block. The UE may assume that the same precoder applies on the two PRBs within a PRG.

9.1.6.4 Antenna ports quasi co-location for DMRS-based SPDCCH

For a given serving cell, if the UE is configured to monitor DMRS-based SPDCCH in slots/subslots where the UE is configured via higher layer signalling to receive slot/subslot-PDSCH data transmissions according to transmission modes 8 and 9,

– the UE may assume the antenna ports 0 – 3, 107 of the serving cell are quasi co-located (as defined in [3]) with respect to Doppler shift, Doppler spread, average delay, and delay spread.

– if the UE is configured by higher layers to decode slot/subslot-PDSCH according to quasi co-location Type-A as described in Clause 7.1.10

– the UE may assume the antenna ports 0 – 3, 107 of the serving cell are quasi co-located (as defined in [3]) with respect to Doppler shift, Doppler spread, average delay, and delay spread.

– if the UE is configured by higher layers to decode slot/subslot-PDSCH according to quasi co-location Type-B as described in Clause 7.1.10

– the UE may assume antenna ports 15 – 22 corresponding to the higher layer parameter qcl-CSI-RS-ConfigNZPId-r11 (defined in Clause 9.1.4.3) and antenna port 107 are quasi co-located (as defined in [3]) with respect to Doppler shift, Doppler spread, average delay, and delay spread.