# lteDCIInfo

## Syntax

``info = lteDCIInfo(enb)``
``info = lteDCIInfo(enb,chs)``

## Description

example

````info = lteDCIInfo(enb)` returns a structure indicating the minimum possible payload sizes, including zero-padding bits when necessary, for all downlink control information (DCI) message formats, given the cell-wide configuration in `enb`. This syntax uses default values for the UE-specific channel configuration.To access the individual bit field sizes for each separate format, use the related function `lteDCI`. TS 36.212 [1], Section 5.3.3.1, along with the referenced procedures of TS 36.213 [2], specify the rules defining the relationship between the bit field sizes and message padding per format, and the cell-wide and UE-specific parameters.For information on link bandwidth assignment, see Specifying Number of Resource Blocks.```
````info = lteDCIInfo(enb,chs)` permits formats to be extended with additional bit fields on a per-UE basis, using the UE-specific channel configuration, `chs`.```

## Examples

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Find the minimum payload sizes of all DCI message formats for NDLRB = 50 (10 MHz symmetric link bandwidth), FDD duplexing, and PDCCH transmission.

```enb = struct('NDLRB',50,'DuplexMode','FDD','CellRefP',1); lteDCIInfo(enb)```
```ans = struct with fields: Format0: 27 Format1: 31 Format1A: 27 Format1B: 28 Format1C: 13 Format1D: 28 Format2: 43 Format2A: 41 Format2B: 41 Format2C: 42 Format2D: 45 Format3: 27 Format3A: 27 Format4: 36 Format5: 27 Format5A: 27 ```

Using the UE-specific channel structure, `chs`, extend the DCI formats to include optional fields dependent on the target UE protocol configuration.

Show the minimum DCI message size per format for `NDLRB` = 50 (10 MHz symmetric link bandwidth), FDD duplexing, and PDCCH transmission.

```enb = struct('NDLRB',50,'DuplexMode','FDD','CellRefP',1); dciout = lteDCIInfo(enb)```
```dciout = struct with fields: Format0: 27 Format1: 31 Format1A: 27 Format1B: 28 Format1C: 13 Format1D: 28 Format2: 43 Format2A: 41 Format2B: 41 Format2C: 42 Format2D: 45 Format3: 27 Format3A: 27 Format4: 36 Format5: 27 Format5A: 27 ```

Default settings for the UE-specific channel structure, `chs`, are:

```chs.ControlChannelType = 'PDCCH'; chs.SearchSpace = 'UESpecific'; chs.EnableCarrierIndication = 'Off'; chs.EnableMultipleCSIRequest = 'Off'; chs.EnableSRSRequest = 'Off'; chs.NTxAnts = 1;```

Enable carrier indication, and show the sizes per format when the DCI message is configured to include the UE-specific 3 bit carrier indicator field (CIF).

```chs.EnableCarrierIndication = 'On'; dciout = lteDCIInfo(enb,chs)```
```dciout = struct with fields: Format0: 29 Format1: 34 Format1A: 29 Format1B: 31 Format1C: 13 Format1D: 31 Format2: 46 Format2A: 43 Format2B: 43 Format2C: 45 Format2D: 47 Format3: 27 Format3A: 27 Format4: 39 Format5: 29 Format5A: 29 ```

The sizes have not changed for formats 1C/3/3A, because the CIF does not apply to them. Also, because of the padding rules, the original lengths for some of the formats increased by less than 3 bits. These lengths are for formats mapped into the UE-specific search space, not formats 3/3A.

Change the UE-specific parameter to map the CIF into the PDCCH common search space.

```chs.SearchSpace = 'Common'; dciout = lteDCIInfo(enb,chs)```
```dciout = struct with fields: Format0: 27 Format1: 34 Format1A: 27 Format1B: 31 Format1C: 13 Format1D: 31 Format2: 46 Format2A: 43 Format2B: 43 Format2C: 45 Format2D: 47 Format3: 27 Format3A: 27 Format4: 39 Format5: 27 Format5A: 27 ```

When the DCI message is configured for PDCCH-common search space, the format 0/1A length returns to its original size.

As specified in TS 36.212, with regard to search space, these points apply:

• Only formats 0/1A/1C can be mapped into either the PDCCH common or UE-specific search spaces.

• Formats 3/3A can be mapped into the common search space only.

• All other formats are mapped into UE-specific spaces only.

• There is no common search space for the EPDCCH.

## Input Arguments

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DCI message format and bandwidth, specified as a structure that can contain the following fields.

Parameter FieldRequired or OptionalValuesDescription
`NDLRB`Required

Scalar integer from 6 to 110

Number of downlink resource blocks. (${N}_{\text{RB}}^{\text{DL}}$)

For information on link bandwidth assignment, see Specifying Number of Resource Blocks.

`NULRB`Required

Scalar integer from 6 to 110

Number of uplink resource blocks. (${N}_{\text{RB}}^{\text{UL}}$)

For information on link bandwidth assignment, see Specifying Number of Resource Blocks.

`CellRefP`Optional

1 (default), 2, 4

Number of cell-specific reference signal (CRS) antenna ports

`DuplexMode`Optional

`'FDD'` (default), `'TDD'`

Duplexing mode, specified as:

• `'FDD'` for Frequency Division Duplex or

• `'TDD'` for Time Division Duplex

User-equipment-related (UE-related) channel configuration, specified as a structure containing these UE-specific fields.

Note

All fields in `chs` are optional. The presence of these optional fields depends on:

• Whether the transmission of DCI message is in a PDCCH using common search space mapping or in an EDPCCH.

• The release-specific features configured at the destination UE.

These additional UE-specific bit fields are off by default.

Option to enable carrier indication field (CIF) in the UE configuration, specified as `'Off'` or `'On'`. By default, `EnableCarrierIndication` is disabled. When `EnableCarrierIndication` is enabled (`'On'`), the CIF is present in the UE-specific configuration.

Data Types: `char` | `string`

Physical control channel type used to carry DCI formats, specified as `'PDCCH'` or `'EPDCCH'`. The setting for `ChannelControlType` affects the presence of the HARQ-ACK resource offset field and message padding.

Data Types: `char` | `string`

Search space mapping for DCI formats 0/1A/1C, specified as `'UESpecific'` or `'Common'`. This field is only applicable for PDCCH. None of the additional fields can be present when formats 0 or 1A are mapped into the PDCCH common search space.

Data Types: `char` | `string`

Option to enable SRS request in the UE configuration, specified as `'Off'` or `'On'`. By default, `EnableSRSRequest` is disabled. When `EnableSRSRequest` is enabled (`'On'`), the SRS request field is present in UE-specific formats 0/1A for FDD or TDD and formats 2B/2C/2D for TDD.

Data Types: `char` | `string`

Option to enable multiple CSI requests in the UE configuration, specified as `'Off'` or `'On'`. By default, `EnableMultipleCSIRequest` is disabled. When `EnableMultipleCSIRequest` is enabled (`'On'`), the UE is configured to process multiple channel state information (CSI) requests from cells. Enabling multiple CSI requests affects the length of the CSI request field in UE-specific formats 0 and 4.

Data Types: `char` | `string`

Number of UE transmission antennas, specified as 1, 2, or 4. The number of UE transmission antennas affects the length of the precoding information field in DCI format 4.

Data Types: `double`

Number of sub-channels in V2X PSSCH pool, specified as an integer scalar from 1 to 110. It affects the length of RIV in format 5A

Data Types: `double`

Data Types: `struct`

## Output Arguments

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Payload sizes for all DCI message formats, returned as a structure with the following parameter fields.

Parameter FieldDescriptionValuesData Type
`Format0`

`Format0` payload size. `Format0` is the DCI format used for the scheduling of PUSCH.

Integer`uint64`
`Format1`

`Format1` payload size. `Format1` is the DCI format used for the scheduling of one PDSCH codeword.

Integer`uint64`
`Format1A`

`Format1A` payload size. `Format1A` is the DCI format used for the compact scheduling of one PDSCH codeword and random access procedure.

Integer`uint64`
`Format1B`

`Format1B` payload size. `Format1B` is the DCI format used for the compact scheduling of one PDSCH codeword with precoding information.

Integer`uint64`
`Format1C`

`Format1C` payload size. `Format1C` is the DCI format used for very compact scheduling of one PDSCH codeword.

Integer`uint64`
`Format1D`

`Format1D` payload size. `Format1D` is the DCI format used for the compact scheduling of one PDSCH codeword with precoding and power offset information.

Integer`uint64`
`Format2`

`Format2` payload size. `Format2` is the DCI format used for the scheduling of two PDSCH codewords with precoding information for closed-loop spatial multiplexing.

Integer`uint64`
`Format2A`

`Format2A` payload size. `Format2A` is the DCI format used for the scheduling of two PDSCH codewords with precoding information for open-loop spatial multiplexing.

Integer`uint64`
`Format2B`

`Format2B` payload size. `Format2B` is the DCI format used for the scheduling of dual-layer transmission, for antenna ports 7 and 8.

Integer`uint64`
`Format2C`

`Format2C` payload size. `Format2C` is the DCI format used for the scheduling of up to eight-layer transmission, for antenna ports 7–14, using TM9.

Integer`uint64`
`Format2D`

`Format2D` payload size. `Format2D` is the DCI format used for the scheduling of up to eight-layer transmission, for antenna ports 7–14, using TM10.

Integer`uint64`
`Format3`

`Format3` payload size. `Format3` is the DCI format used for the transmission of transmit power control (TPC) commands for PUCCH and PUSCH with 2-bit power adjustments.

Integer`uint64`
`Format3A`

`Format3A` payload size. `Format3A` is the DCI format used for the transmission of transmit power control (TPC) commands for PUCCH and PUSCH with 1-bit power adjustments.

Integer`uint64`
`Format4`

`Format4` payload size. `Format4` is the DCI format used for the scheduling of PUSCH with multi-antenna port transmission mode.

Integer`uint64`
`Format5`

`Format5` payload size. `Format5` is the DCI format used for the scheduling of PSCCH, and also contains several SCI format 0 fields used for the scheduling of PSSCH.

Integer`uint64`
`Format5A`

`Format5A` payload size. `Format5A` is the DCI format used for the scheduling of V2X PSSCH.

Integer`uint64`

According to the rules defined in TS 36.212 [1], Section 5.3.3, the payload size of DCI `Format0` and `Format1A` should always be the same and either format will be appended with padding bits, if necessary, to fulfill this condition.

None of the DCI format payload sizes should equal the ambiguous sizes defined in TS 36.212 [1], Table 5.3.3.1.2-1. If necessary, padding bits are added to the DCI format payload. When transmitting DCI messages using PDCCH, the ambiguous format payload sizes are 12, 14, 16, 20, 24, 26, 32, 40, 44, and 56.

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### Specifying Number of Resource Blocks

The number of resource blocks specifies the uplink and downlink bandwidth. The LTE Toolbox™ implementation assumes symmetric link bandwidth unless you specifically assign different values to `NULRB` and `NDLRB`. If the number of resource blocks is initialized in only one link direction, then the initialized number of resource blocks (`NULRB` or `NDLRB`) is used for both uplink and downlink. When this mapping is used, no warning is displayed. An error occurs if `NULRB` and `NDLRB` are both undefined.

## References

[1] 3GPP TS 36.212. “Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

[2] 3GPP TS 36.213. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

## Version History

Introduced in R2014a