5G/NR  - DCI  

 

 

 

5G DCI in a Nutshell

 

  • What is it for ?  It is for scheduling physical resources for Downlink(PDSCH) and Uplink(PUSCH)
  • Types of DCIs : 0_0, 0_1,1_0,1_1,2_0,2_1,2_2,2_2,2_3,2_4,2_5,2_6,3_0,3_1
  • Most Commonly Used Types : 1_0,1_1 for DL Schduling and 0_0,0_1 for UL Scheduling
  • How UE can figure out which DCI it should decode ? : By checking RNTI masking the DCI
  • Physical Channels carrying DCI : PDCCH

5G DCI in Detail

DCI stands for Downlink Control Information. Simply put, it has several major functionalities as follows :

  • Carrying the information to schedule (allocate physical resources) for Downlink Data (PDSCH)
  • Carrying the information to schedule (allocate physical resources) for Uplink Data (PUSCH)
  • Carrying the information to adjust Uplink Power (PUSCH, PUCCH power) for power control

The main purpose of DCI (Downlink Control Information) is the same as DCI in LTE(I strongly recommend you to read LTE DCI page first if you are not so familiar with what the DCI does). That is, it is a special set of information which schedules downlink data channel (e.g, PDSCH) or uplink data channel (e.g, PUSCH).

Followings are the list of DCI types and its contents defined in 38.212 - 7.3 Downlink control information.

< 38.212 - Table 7.3.1-1: DCI formats >

DCI Format

Usage

Format 0_0

Scheduling of PUSCH in one cell

Format 0_1

Scheduling of PUSCH in one cell

    DCI format 0_1 with CRC scrambled by C-RNTI

    DCI format 0_1 with CRC scrambled by CS-RNTI

Format 1_0

Scheduling of PDSCH in one cell

    DCI format 1_0 with CRC scrambled by C-RNTI

    DCI format 1_0 with CRC scrambled by C-RNTI for PDCCH Order

    DCI format 1_0 with CRC scrambled by RA-RNTI

    DCI format 1_0 with CRC scrambled by TC-RNTI

    DCI format 1_0 with CRC scrambled by SI-RNTI

    DCI format 1_0 with CRC scrambled by P-RNTI

Format 1_1

Scheduling of PDSCH in one cell

Format 2_0

Notifying a group of UEs of the slot format

Format 2_1

Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE

Format 2_2

Transmission of TPC commands for PUCCH and PUSCH

Format 2_3

Transmission of a group of TPC commands for SRS transmissions by one or more UEs

Format 2_4

Notifying the PRB(s) and OFDM symbol(s) where UE cancels the corresponding UL transmission from the UE

Format 2_5

Notifying the availability of soft resources

Format 2_6

Notifying the power saving information outside DRX Active Time for one or more UEs

Format 3_0

Scheduling of NR sidelink in one cell

Format 3_1

Scheduling of LTE sidelink in one cell

NOTE : The contents of the table shown here is based on 38.212. This specification is very dry. As any other 3GPP spcecification, it just describes 'what should be done' and does not describe anything on the background story. To get any further technical background, you need to follow through a lot of TDocs. However, unless you are a firmware or DSP engineering implementing the physical channel, it will be very difficult to keep track of all the TDocs. One trick that I would recommend is to go through several latest TDocs not far away from TS (Technical Specification) because those TDocs usually have the summary of past stories and more detailed design concept. I put several TDocs under Reference section that might help you to get some background stories.

Once a DCI data is constructed, it goes to the channel coding process and transmitted over PDCCH. This process is described in followng page.

Format 0_0

This is used for the scheduling of PUSCH in one cell.

Field (Item)

Bits

Reference

Identifier for DCI formats

1

 

Frequency domain resource assignment

X

Variable with UL BWP N_RB.

Indicate PRB location within the BWP.

The number of bits and the value is determined as described here.

Time domain resource assignment

4

Carries the row index of the items in pusch_allocationList in RRC

Frequency Hopping Flag

1

 

Modulation and coding scheme

5

38.214 - 6.1.4 (See this table)

New data indicator

1

 

Redundancy version

2

0,1,2,3

HARQ process number

4

 

TPC command for scheduled PUSCH

2

38.213 - Table 7.1.1-1

UL/SUL indicator

0 or 1

0 bit : SUL not figured

1 bit : SUL configured

Frequency domain resource assignment

The number of bits(bit length) for this field is determined by following formula

     

    The meaning of varies depending on the search space where DCI_0_0 is transmitted.

    • When stransmitted in common search space,

        • it indicates the size of the Initial Bandwidth Part

    • When stransmitted in UE specific search space and meets following criteria

          • the total number of different DCI sizes monitored per slot <= 4

          the total number of different DCI sizes with C-RNTI monitored per slot <= 3

        it indicates the size of the Active Bandwidth Part

The value of this field is determined as follows.

    Case 1 : PUSCH hopping = True and Resource allocation type 1

      • MSB bits are used to indicate the frequency offset
        • = 1 if  Frequency-hopping-offsets-set contains two offset values
        • = 2 if  Frequency-hopping-offsets-set contains four offset values
        • Remaining Bits indicates PUSCH RIV

     

    Case 2 : PUSCH hopping = False and Resource allocation type 1

      • the whole bits of this field indicates PUSCH RIV

 

< 38.214 v15.1 - Table 6.1.4.1-1: MCS index table for PUSCH with transform precoding and 64QAM >

MCS Index

I_MCS

Modulation Order

Qm

Target code Rate

R x 1024

Spectral

efficiency

0

q

240/ q

0.2344

1

q

314/ q

0.3066

2

2

193

0.377

3

2

251

0.4902

4

2

308

0.6016

5

2

379

0.7402

6

2

449

0.877

7

2

526

1.0273

8

2

602

1.1758

9

2

679

1.3262

10

4

340

1.3281

11

4

378

1.4766

12

4

434

1.6953

13

4

490

1.9141

14

4

553

2.1602

15

4

616

2.4063

16

4

658

2.5703

17

6

466

2.7305

18

6

517

3.0293

19

6

567

3.3223

20

6

616

3.6094

21

6

666

3.9023

22

6

719

4.2129

23

6

772

4.5234

24

6

822

4.8164

25

6

873

5.1152

26

6

910

5.332

27

6

948

5.5547

28

1

reserved

29

2

reserved

30

4

reserved

31

6

reserved

< 38.213 v2.0.0 - Table 7.1.1-1: Mapping of TPC Command Field in DCI format 0_0, DCI format 0_1, or DCI format 2_2, or DCI format 2_3 having CRC parity bits scrambled by TPC-PUSCH-RNTI or TPC-SRS-RNTI, to absolute and accumulated  d_PUSCH,c values >

Format 0_1

This is used for the scheduling of PUSCH in one cell.

< DCI format 0_1 with CRC scrambled by C-RNTI > 

Field (Item)

Bits

Reference

Identifier for DCI formats

1

 

Carrier indicator

0 or 3

 

UL/SUL Indicator

0,1

0 - bit for UE not configured with SUL in the cell

1 - bit for UEs configured with SUL in the cell

      : according to Table 7.3.1.1.1-1

      0 : non-spplementary Uplink

      1 : spplementary Uplink

Bandwidth part indicator

0,1,2

Determined by BandwidthPart-Config in higher layer message and 38.212 - Table 7.3.1.1.2-1

Frequency domain resource assignment

Variable

Variable with Resource Allocation Type

Time domain resource assignment

4

Carries the row index of the items in pusch_allocationList in RRC

Number of Bit Length is determined by log(I,2), where I is the number of elements in pusch_allocationList in RRC

Frequency Hopping Flag

0,1

 

Modulation and coding scheme

5

38.214 - 6.1.4 (See this table)

New data indicator

1

 

Redundancy version

2

0,1,2,3

HARQ process number

4

 

1st Downlink assignment index

1,2

 

2nd Downlink assignment index

0,2

 

TPC command for scheduled PUSCH

2

 

SRS resource indicator

Variable

Determined by RRC Parameter SRS-SetUse

Precoding information and number of layers

(TPMI)

0,2,3,4,5,6

Determined by ulTxConfig, Number of Antenna ports, PUSCH-tp, ULmaxRank

Antenna ports

2,3,4,5

Determined by PUSCH-tp, DL-DMRS-config-type, DL-DMRS-config-max-len, Rank

SRS request

2

Table 7.3.1.1.2-24

CSI request

0,1,2,3,4,5,6

Determined by ReportTriggerSize in RRC message.

See Configure Aperiodic Trigger section for the details.

CBG transmission information

0,2,4,6,8

Determined by maxCodeBlockGroupPerTransportblock in RRC message

PTRS - DMRS Association

0,2

Determined by UL-PTRS-present, PUSCH-tp in RRC Message

beta_offsetr Indicator

0,2

0 - if uci-on-PUSCH.dynamic = Not Configured

2 - otherwise, see Table 7.3.1.1.2-27

DMRS Sequence Initialization

0,1

0 - if PUSCH-tp=Disabled

1 - if PUSCH-tp=Enabled

UL-SCH Indicator

1

0 - UL-SCH shall not be transmitted on the PUSCH

1 - UL-SCH shall be transmitted on the PUSCH

 

< DCI format 0_1 with CRC scrambled by CS-RNTI > 

Field (Item)

Bits

Reference

Identifier for DCI formats

1

 

Carrier indicator

0 or 3

 

DFI Flag

0 or 1

1 bit when cg-RetransmissionTimer is configured

  • value 0 : activating or releasing type 2 CG transmission
  • value 1 : CG-DFI

HARQ-ACK bitmap

16

HARQ process indices are mapped in ascending order from MSB to LSB of the bitmap

TPC command for scheduled PUSCH

2

 

All the remaining bits

 

set to 0

 

< 38.212 v17.3.0 - Table 7.3.1.1.1-1: UL/SUL indicator >

Value of UL/SUL indicator

Uplink

0

The non-supplementary uplink

1

The supplementary uplink

 

< 38.212 v15.3.0 - Table 7.3.1.1.2-1: Bandwidth part indicator  >

Value of BWP indicator field

Bandwidth part

1 bit

2 bits

0

0

First bandwidth part configured by higher layers

1

1

Second bandwidth part configured by higher layers

 

10

Third bandwidth part configured by higher layers

 

11

Fourth bandwidth part configured by higher layers

 

< Frequency domain resource assignment >

The bit length of this field is determined as follows.

Resource Allocation Type

Mumber of Bits

Resource Allocation Type 0 only

, P is defined in 38.214 Table 6.1.2.2.1-1

Resource Allocation Type 1 only

Resource Allocation Type 0 and Type 1

Bit Length :

      

MSB Indicates Resource Allocation Type

     0 : Resource Allocation Type 0

     1 : Resource Allocation Type 1

 

The value of this field is determined as follows :

  • Resource Allocation Type 0 only : Bitmap determined as described here.
  • Resource Allocation Type 1 only : Determined depending on PUSCH Hopping field as follows
    • Case 1 : PUSCH hopping = True
        • MSB bits are used to indicate the frequency offset
          • = 1 if  Frequency-hopping-offsets-set contains two offset values
          • = 2 if  Frequency-hopping-offsets-set contains four offset values
          • Remaining Bits indicates PUSCH RIV
    • Case 2 : PUSCH hopping = False
        • the whole bits of this field indicates PUSCH RIV

 

< 38.214-v15.3.0 Table 6.1.2.2.1-1: Nominal RBG size P >

Carrier Bandwidth Part Size

Configuration 1

Configuration 2

1-36

2

4

37-72

4

8

73-144

8

16

145-275

16

16

NOTE : Which RBG(Resource Block Group) size to be used is determined by PUSCH-Config.rbg-Size in RRC message from gNB

< SRS resource indicator >

SRS-ResourceSet.usage

Bit Length of SRS Resource Indicator

CodeBook

N_SRS is the number of configured SRS resources in the SRS resource set associated with  "usage".

NonCodeBook

 

 

< 38.212-Table 7.3.1.1.2-24: SRS request >

Value of SRS request field

Triggered aperiodic SRS resource set(s)

00

No aperiodic SRS resource set triggered

01

SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 1

10

SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 2

11

SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 3

 

< Precoding information and number of layers >

txConfig(UL)

Antenna

PUSCH-tp

maxRank

CodebookSubset

Bit Length

Table in 38.212

NonCodeBook

 

 

 

 

0

 

CodeBook

4 ports

Disabled

2 or 3 or 4

 

4 or 5 or 6

7.3.1.1.2-2

CodeBook

4 ports

Disabled

 

 

2 or 4 or 5

7.3.1.1.2-3

Enabled

1

 

CodeBook

2 ports

 

2

 

3 or 4

7.3.1.1.2-4

CodeBook

2 ports

 

1

 

2 or 3

7.3.1.1.2-5

NOTE : PUSCH-tp indicates PUSCH Transform Precoding. Refer to Transform Precoding section in Waveform Page if you want to know what this is.

NOTE : txConfig, PUSCH-tp, maxRank, codebook Subset are specified by PUSCH-Config in RRC.

 

<  Antenna ports >

PUSCH-tp

DMRS-config-type

DMRS-config-max-len

Rank

Bit Lenth

Table in 38.212

Enabled

1

1

 

2

7.3.1.1.2-6

1

2

 

4

7.3.1.1.2-7

Disabled

1

1

1

3

7.3.1.1.2-8

1

1

2

3

7.3.1.1.2-9

1

1

3

3

7.3.1.1.2-10

1

1

4

3

7.3.1.1.2-11

Disabled

1

2

1

4

7.3.1.1.2-12

1

2

2

4

7.3.1.1.2-13

1

2

3

4

7.3.1.1.2-14

1

2

4

4

7.3.1.1.2-15

Disabled

2

1

1

4

7.3.1.1.2-16

2

1

2

4

7.3.1.1.2-17

2

1

3

4

7.3.1.1.2-18

2

1

4

4

7.3.1.1.2-19

Disabled

2

2

1

5

7.3.1.1.2-20

2

2

2

5

7.3.1.1.2-21

2

2

3

5

7.3.1.1.2-22

2

2

4

5

7.3.1.1.2-23

NOTE : PUSCH-tp indicates PUSCH Transform Precoding. Refer to Transform Precoding section in Waveform Page if you want to know what this is.

 

<  PTRS - DMRS Association >

UL-PTRS-present

PUSCH-tp

UL PTRS port

UL-PTRS-ports

Bit Length

Table in 38.212

OFF

Disabled

 

 

0

N/A

ON

Enabled

 

 

0

N/A

ON

Disabled

 

 

0

N/A

Otherwise

0

1

2

7.3.1.1.2-25

0

2

2

7.3.1.1.2-26

1

2

2

7.3.1.1.2-26

Format 1_0

This is used for the scheduling of PDSCH in one cell.

< DCI format 1_0 with CRC scrambled by C-RNTI >  

Field (Item)

Bits

Reference

Identifier for DCI formats

1

Always set to 1, meaning this is for DL

Frequency domain resource assignment

Variable

Variable with DL BWP N_RB

     

Time domain resource assignment

4

Carries the row index of the items in pdsch_allocationList in RRC

VRB-to-PRB mapping

1

According to 38.212 Table 7.3.1.1.2-33

     0 : Non-Interleaved

     1 : Inverleaved

Modulation and coding scheme

5

38.214  - Table 5.1.3.1-1: MCS index table 1 for PDSCH

38.214 - Table 5.1.3.1-2: MCS index table 2 for PDSCH

New data indicator

1

 

Redundancy version

2

 

HARQ process number

4

 

Downlink assignment index

2

 

TPC command for scheduled PUCCH

2

 

PUCCH resource indicator

3

See here , here

PDSCH-to-HARQ_feedback timing indicator

3

maps to k1={1,2,3,4,5,6,7,8} - NOTE 2

NOTE 1 : The meaning of varies depending on the search space where DCI_1_0 is transmitted.

    When stransmitted in common search space,

      it indicates the size of the Initial Bandwidth Part

    When stransmitted in UE specific search space and meets following criteria

        the total number of different DCI sizes monitored per slot <= 4

        the total number of different DCI sizes with C-RNTI monitored per slot <= 3

      it indicates the size of the Active Bandwidth Part

NOTE 2 : In case of DCI 1_1, this field indicates the index value of dl-DataToUL-ACK, dl-DataToUL-ACK-r16 configured in RRC, but this field in DCI 1_0 refers to the index of pre-defined set {1,2,3,4,5,6,7,8}. This is based on following specification.

    38.213-9.2.3

    For DCI format 1_0, the PDSCH-to-HARQ_feedback timing indicator field values map to {1, 2, 3, 4, 5, 6, 7, 8}. For a DCI format, other than DCI format 1_0, scheduling a PDSCH reception or a SPS PDSCH release, the PDSCH-to HARQ_feedback timing indicator field values, if present, map to values for a set of number of slots provided by dl- DataToUL-ACK, dl-DataToUL-ACK-r16, or dl-DataToUL-ACKForDCIFormat1_2

< DCI format 1_0 with CRC scrambled by C-RNTI for PDCCH Order>  

Field (Item)

Bits

Reference

Identifier for DCI formats

1

Always set to 1, meaning this is for DL

Frequency domain resource assignment

Variable

All Ones

Random Access Preamble index

6

6 bits according to ra-PreambleIndex

UL/SUL indicator

1

NOTE 1

SS/PBCH index

6

 NOTE 2

PRACH Mask index

4

 NOTE 3

Reserved bits

12 or 10

 NOTE 4

NOTE 1 : If the value of the "Random Access Preamble index" is not all zeros and if the UE is configured with supplementaryUplink in ServingCellConfig in the cell, this field indicates which UL carrier in the cell to transmit the PRACH according to Table 7.3.1.1.1-1( 0 = Non Supplimentary Uplink, 1 = Supplementary Uplink); otherwise, this field is reserved

NOTE 2 : If the value of the "Random Access Preamble index" is not all zeros, this field indicates the SS/PBCH that shall be used to determine the RACH occasion for the PRACH transmission; otherwise, this field is reserved.

NOTE 3 : If the value of the "Random Access Preamble index" is not all zeros, this field indicates the RACH occasion associated with the SS/PBCH indicated by "SS/PBCH index" for the PRACH transmission, according to Clause 5.1.1 of  38.321; otherwise, this field is reserved

NOTE 4 : 12 bits for operation in a cell with shared spectrum channel access; otherwise 10 bits

< DCI format 1_0 with CRC scrambled by RA-RNTI >  

: This is used to schedule RAR (Msg2) in RACH Procedure

Field (Item)

Bits

Reference

Frequency domain resource assignment

Variable

Variable with DL BWP N_RB

     

indicates the size of CORESET 0

Time domain resource assignment

4

Carries the row index of the items in pdsch_allocationList in RRC

VRB-to-PRB mapping

1

According to 38.212 Table 7.3.1.1.2-33

     0 : Non-Interleaved

     1 : Inverleaved

Modulation and coding scheme

5

38.214  - Table 5.1.3.1-1: MCS index table 1 for PDSCH

38.214 - Table 5.1.3.1-2: MCS index table 2 for PDSCH

TB Scaling

2

 

Reserved

16

Reserved

The meaning of varies depending on the search space where DCI_1_0 is transmitted.

    When stransmitted in common search space in CORESET 0 ,

      it indicates the size of the Initial Bandwidth Part

    When stransmitted in UE specific search space and meets following criteria

        the total number of different DCI sizes monitored per slot <= 4

        the total number of different DCI sizes with C-RNTI monitored per slot <= 3

      it indicates the size of the Active Bandwidth Part

TB Scaling is special parameters affecting the determination of Transport Block Size. This factor is multiplied to the result of the calculated Ninfo value.

< 38.214 - Table 5.1.3.2-2: Scaling factor of Ninfo for P-RNTI, RA-RNTI and MSGB-RNTI >

 

< DCI format 1_0 with CRC scrambled by TC-RNTI >  

: This is used to schedule Contention Resolution (Msg4) in RACH Procedure

Field (Item)

Bits

Reference

Identifier for DCI formats

1

Always set to 1, meaning this is for DL

Frequency domain resource assignment

Variable

Variable with DL BWP N_RB

     

indicates the size of CORESET 0

Time domain resource assignment

4

Carries the row index of the items in pdsch_allocationList in RRC

VRB-to-PRB mapping

1

According to 38.212 Table 7.3.1.1.2-33

     0 : Non-Interleaved

     1 : Inverleaved

Modulation and coding scheme

5

38.214  - Table 5.1.3.1-1: MCS index table 1 for PDSCH

38.214 - Table 5.1.3.1-2: MCS index table 2 for PDSCH

New data indicator

1

 

Redundancy version

2

 

HARQ process number

4

 

Downlink assignment index

2

Reserved

TPC command for scheduled PUCCH

2

 

PUCCH resource indicator

3

See here , here

PDSCH-to-HARQ_feedback timing indicator

3

Row number(index) of K1

The meaning of varies depending on the search space where DCI_1_0 is transmitted.

    When stransmitted in common search space in CORESET 0 ,

      it indicates the size of the Initial Bandwidth Part

    When stransmitted in UE specific search space and meets following criteria

        the total number of different DCI sizes monitored per slot <= 4

        the total number of different DCI sizes with C-RNTI monitored per slot <= 3

      it indicates the size of the Active Bandwidth Part

 

< DCI format 1_0 with CRC scrambled by SI-RNTI >  

: This is used to schedule SIB1 and other SIB messages

Field (Item)

Bits

Reference

Frequency domain resource assignment

Variable

Variable with DL BWP N_RB

     

indicates the size of CORESET 0

Time domain resource assignment

4

Carries the row index of the items.

VRB-to-PRB mapping

1

According to 38.212 Table 7.3.1.1.2-33

     0 : Non-Interleaved

     1 : Inverleaved

Modulation and coding scheme

5

38.214  - Table 5.1.3.1-1: MCS index table 1 for PDSCH

38.214 - Table 5.1.3.1-2: MCS index table 2 for PDSCH

Redundancy Version

2

 

System Information Indicator

1

0 : SIB 1

1 : SI messages

Reserved

15

Reserved

[NOTE 1] SIB1 DCI refer to SI-RNTI / Type0Common in 38.214 - Table 5.1.2.1.1-1. As you see in the table, different TimeDomainResourceAllocation table is used depending on SSB/CORESET Multiplexing Pattern as summarized in the following table.

SSB/CORESET Multiplexing Pattern

TimeDomainAllocation To Apply

3GPP Table

1

Default A for Normal CP

38.214-Table 5.1.2.1.1-2

2

Default B

38.214-Table 5.1.2.1.1-4

3

Defualt C

38.214-Table 5.1.2.1.1-5

 

< DCI format 1_0 with CRC scrambled by P-RNTI>  

: This is used to schedule Paging messages

Field (Item)

Bits

Reference

Short Message Indicator

2

Refer to 38.212 - Table 7.3.1.2.1-1

Short Messages

8

This field is set as reserved when 'Short Message Indicator' field is 01.

Refer to 38.331 - Table 6.5-1

Frequency domain resource assignment

Variable

Variable with DL BWP N_RB

     

indicates the size of CORESET 0

Time domain resource assignment

4

Carries the row index of the items in pdsch_allocationList in RRC

VRB-to-PRB mapping

1

According to 38.212 Table 7.3.1.1.2-33

     0 : Non-Interleaved

     1 : Inverleaved

Modulation and coding scheme

5

38.214  - Table 5.1.3.1-1: MCS index table 1 for PDSCH

38.214 - Table 5.1.3.1-2: MCS index table 2 for PDSCH

TB Scaling

2

 

Reserved

6

Reserved

 

< 38.212 - Table 7.3.1.2.1-1: Short Message indicator >

Bit Field

Short Message Indicator

00

Reserved

01

Only scheduling information for Paging is present in the DCI

10

Only short message is present in the DCI

11

Both scheduling information for Paging and short message are present in the DCI

 

< 38.331 - Table 6.5-1: Short messages >

Bit

Short Message Indicator

1

systemInfoModification

If set to 1: indication of a BCCH modification other than SIB6, SIB7 and SIB8.

2

etwsAndCmasIndication

If set to 1: indication of an ETWS primary notification and/or an ETWS secondary notification and/or a CMAS notification

3-[8]

Not used in this release of the specification, and shall be ignored by UE if received.

Format 1_1

This is used for the scheduling of PDSCH in one cell.

Field (Item)

Bits

Reference

Carrier indicator

0,3

 

Identifier for DCI formats

1

Always set to 1, indicating a DL DCI format

Bandwidth part indicator

0,1,2

 

Frequency domain resource assignment

Variable

Variable with Resource Allocation Type

Time domain resource assignment

4

Carries the row index of the items in pdsch_allocationList in RRC

VRB-to-PRB mapping

0,1

0 bit if only resource allocation type 0 is configured or if interleaved VRB-to-PRB mapping is not configured by high layers;

1 bit according to Table 7.3.1.1.2-33 otherwise, only applicable to resource allocation type 1

PRB bundling size indicator

0,1

0 bit if the higher layer parameter prb-BundlingType is not configured or is set to 'static'

1 bit if the higher layer parameter prb-BundlingType is set to 'dynamic'

Rate matching indicator

0,1,2

Bit size is determined by higher layer parameters rateMatchPatternGroup1 and rateMatchPatternGroup2.

ZP CSI-RS Trigger

0,1,2

 

Modulation and coding scheme [TB1]

5

 

New data indicator [TB1]

1

 

Redundancy version [TB1]

2

 

Modulation and coding scheme [TB2]

5

 

New data indicator [TB2]

1

 

Redundancy version [TB2]

2

 

HARQ process number

4

 

Downlink assignment index

0,2,4

4 bits if more than one serving cell are configured in the DL and the higher layer parameter pdsch-HARQACK-Codebook=dynamic, where the 2 MSB bits are the counter DAI and the 2 LSB bits are the total DAI;

2 bits if only one serving cell is configured in the DL and the higher layer parameter pdsch-HARQ-ACKCodebook= dynamic, where the 2 bits are the counter DAI;

0 bits otherwise.

TPC command for scheduled PUCCH

2

 

PUCCH resource indicator

3

See here , here

PDSCH-to-HARQ_feedback timing indicator

0,1,2,3

Row number(index) of K1

Number of bit is determined by log2(I). 'I' is the number of elements in the IE PUCCH-Config.dl-DataToUL-ACK

Antenna port(s) and number of layers

4,5,6

Determined by

    dmrs Configuration Type and max Length

See this summary table

Transmission configuration indication

0,3

0 bit if higher layer parameter tci-PresentInDCI is not enabled;

3 bits otherwise (See QCL page)

SRS request

2

 

CBG transmission information(CBGTI)

0,2,4,6,8

 

CBG flushing out information(CBGFI)

0,1

 

DMRS sequence initialization

1

 

< Antenna port(s) and number of layers >

dmrs-Type

maxLength

Bit Field Length

Table in 38.212

1

1

4

Table 7.3.1.2.2-1

1

2

5

Table 7.3.1.2.2-2

2

1

5

Table 7.3.1.2.2-3

2

1

6

Table 7.3.1.2.2-4

Format 2_0

This is used for notifying following information to UE. This DCI is scrambled by SFI_RNTI

  • Slot format
  • COT(Channel Occupancy Time) duration
  • Available RB set
  • Search space set group switching

If the higher layer parameter slotFormatCombToAddModList is configured

    Field (Item)

    Bits

    Reference

    Identifier for DCI formats

    1

     

    Slot format indicator

    Variable

    Bit size is determined by RRC message here

Slot format indicator : a Bit string indicating Slot format indicator 1, Slot format indicator 2, , Slot format indicator N

If the higher layer parameter availableRB-SetsToAddModList is configured

    Field (Item)

    Bits

    Reference

    Identifier for DCI formats

    1

     

    Available RB set Indicator

    Variable

    Bit size is determined by RRC message here

Available RB set Indicator : a Bit string indicating Available RB set Indicator 1, Available RB set Indicator 2, , Available RB set Indicator N

If the higher layer parameter co-DurationsPerCellToAddModList is configured

    Field (Item)

    Bits

    Reference

    Identifier for DCI formats

    1

     

    COT duration indicator

    Variable

    Bit size is determined by RRC message here

COT duration indicator : a Bit string indicating COT duration indicator 1, COT duration indicator 2, , COT duration indicator N

If the higher layer parameter switchTriggerToAddModList is configured

    Field (Item)

    Bits

    Reference

    Identifier for DCI formats

    1

     

    Search space set group switching flag

    Variable

    Bit size is determined by RRC message here

Search space set group switching flag : a Bit string indicating Search space set group switching flag1, Search space set group switching flag 2, , Search space set group switching flag N. (Details are in 38.213 - 11.1.1)

NOTE : Not every UE would support this DCI. That is, supporting DCI 2_0 decoding depends on UE capability. UE Capability Information related to DCI 2_0 decoding are listed below.

    Phy-ParametersXDD-Diff ::= SEQUENCE {

        dynamicSFI                                   ENUMERATED {supported} OPTIONAL,

        ...

    }

     

    Phy-ParametersFRX-Diff ::= SEQUENCE {

        dynamicSFI                                   ENUMERATED {supported} OPTIONAL,

        ...

    }

     

    SharedSpectrumChAccessParamsPerBand-r16 ::= SEQUENCE {

        ...

        dci-AvailableRB-Set-r16                  ENUMERATED {supported} OPTIONAL,

        dci-ChOccupancyDuration-r16          ENUMERATED {supported} OPTIONAL,

        ...

    ]

Format 2_1

This is used for notifying the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE. This DCI is scrambled by INT-RNTI.

Field (Item)

Bits

Reference

Identifier for DCI formats

1

  

Pre-emption indication

Variable

  

The size of DCI format 2_1 is configurable by higher layers up to 126 bits and each Pre-emtion indication is 14 bits(Details are in 38.213 - 11.2)

Format 2_2

This is used for the transmission of TPC commands for PUCCH, PUSCH. This DCI is scrambled by scrambled by TPC-PUSCH-RNTI or TPC-PUCCH-RNTI.

Field (Item)

Bits

Reference

Identifier for DCI formats

1

  

block number 1, block number 2,, block number N

Variable

  

Following fields are defined for each block

Field (Item)

Bits

Reference

Closed loop indicator

0,1

  

TPC Command

2 bite

  

Format 2_3

This is used for the transmission of a group of TPC commands for SRS transmissions by one or more UEs. Along with a TPC command, a SRS request may also be transmitted.

Field (Item)

Bits

Reference

Identifier for DCI formats

1

  

block number 1, block number 2,, block number B

Variable

  

Following fields are defined for each block

If the UE is configured with higher layer parameter srs-TPC-PDCCH-Group = typeA for an UL without PUCCH and

PUSCH or an UL on which the SRS power control is not tied with PUSCH power control

Field (Item)

Bits

Reference

SRS Request

0,2

 

TPC command number 1, TPC command number 2, ..., TPC command number N

variable

 

If the UE is configured with higher layer parameter srs-TPC-PDCCH-Group = typeB for an UL without PUCCH and

PUSCH or an UL on which the SRS power control is not tied with PUSCH power control

Field (Item)

Bits

Reference

SRS Request

0,2

 

TPC command number

2

 

Format 2_4

This DCI is used for notifying the PRB(s) and OFDM symbol(s) where UE cancels the corresponding UL transmission from the UE (Details are in 38.213-11.2A). This is scrambled by ci-RNTI.

Format 2_5

This DCI is used for notifying the availability of soft resources (Details in 38.473-9.3.1). This is scrambled by AI-RNTI.

Format 2_6

This DCI is used for notifying the power saving information outside DRX Active Time for one or more UEs. This is scrambled by PS-RNTI

Structure of DCI format 2_6 is as follows :

    block number 1, block number 2,, block number N

Structure of each block is as follows :

Field (Item)

Bits

Reference

Wake-up indication

1

 

SCell dormancy indication

0,1,2,3,4,5
  • 0 bit if RRC parameter dormancyGroupOutsideActive is not configured
    • '0' indicates to not start the drxonDurationTimer for the next long DRX cycle
    • '1' indicates to start the drxonDurationTimer for the next long DRX cycle
  • 1, 2, 3, 4 or 5 bits bitmap determined according to higher layer parameter dormancyGroupOutsideActiveTime, where each bit corresponds to one of the SCell group(s) configured by higher layers parameter dormancyGroupOutsideActiveTime, with MSB to LSB of the bitmap corresponding to the first to last configured SCell group.

Reference

[1] 3GPP TS 38.212 NR;Multiplexing and channel coding   

[2] 3GPP TSG RAN WG1 Meeting #92  : R1-1802117 : Discussion on DCI contents

[3] 3GPP TSG-RAN WG1 #92 : R1-1802905 : Remaining issues of the DCI contents and formats  

[4] 3GPP TSG RAN WG1 Meeting #92 : R1-1801976 : DCI Contents and Formats

[5] 3GPP TSG RAN WG1 Meeting #92 : R1-1802097 : Remaining issues on MIMO related DCI design

[6] 3GPP TSG RAN WG1 Meeting #92 : R1-1802482 : DCI contents and formats

[7] 3GPP TSG RAN WG1 Meeting #92 : R1-1802597 : Remaining issues in DCI contents and formats  

[8] 3GPP TSG RAN WG1 Meeting #92 : R1-1802209 : Remaining issues on DCI contents and formats

[9] 3GPP TSG RAN WG1 Meeting #92 : R1-1801730 : Open issues on DCI contents and formats

[10] 3GPP TSG RAN WG1 Meeting #92 : R1-1801624 : Remaining issues on DCI content

[11] 3GPP TSG RAN WG1#100bis-e R1-e-Meeting, April 20th 30th, 2020 : Email discussion/approval on special states/indications in available RB set indication and COT duration indication/determination (NR-U DL Signals and Channels)