# lteEPDCCHSpace

EPDCCH search space candidates

## Description

example

[ind,info] = lteEPDCCHSpace(enb,chs) returns a matrix or cell array of EPDCCH ECCE candidate indices, and related dimensional information for the given cell-wide settings structure and EPDCCH transmission configuration structure. Depending on the configuration, the function returns a matrix of candidates for a single EPDCCH set, or a cell array containing one or two matrices of candidates for one or two EPDCCH sets.

## Examples

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EPDCCH Search Space for DCI Format 2A and 1.

For a particular configuration, establish the sizes of DCI messages for format 2A and format 1. Note that for DCI messages conveyed on the EPDCCH, ControlChannelType should be set to 'EPDCCH'.

enb.NDLRB = 50;
enb.CellRefP = 1;
enb.NCellID = 0;
enb.NSubframe = 0;
enb.CFI = 1;
chs.EPDCCHType = 'Localized';
chs.EPDCCHPRBSet = (0:3).';
chs.EPDCCHFormat = 1;
chs.RNTI = 7;
chs.ControlChannelType = 'EPDCCH';

dcisizes = lteDCIInfo(enb,chs);
format2Asize = dcisizes.Format2A
format2Asize = uint64
42
format1size = dcisizes.Format1
format1size = uint64
33

Create the EPDCCH search space candidates for a localized EPDCCH transmission of a DCI format 2A message.

chs.DCIFormat = 'Format2A';
[candidates,info] = lteEPDCCHSpace(enb,chs)
candidates = 4×2

4     7
8    11
12    15
0     3

info = struct with fields:
nEPDCCH: 126
NECCEPerPRB: 4
NEREGPerECCE: 4
NECCEPerEPDCCH: 4
EPDCCHCase: 1
NECCE: 16

Create the candidates for a DCI format 1 message for the same configuration. The DCI format 1 message is smaller than the format 2A message, resulting in a change of case number (info.EPDCCHCase) from 1 to 3. The aggregation level (info.NECCEPerEPDCCH) changes from 4 to 2, resulting in a greater number of candidates.

chs.DCIFormat = 'Format1';
[candidates,info] = lteEPDCCHSpace(enb,chs)
candidates = 6×2

2     3
4     5
6     7
10    11
12    13
14    15

info = struct with fields:
nEPDCCH: 126
NECCEPerPRB: 4
NEREGPerECCE: 4
NECCEPerEPDCCH: 2
EPDCCHCase: 3
NECCE: 16

## Input Arguments

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eNodeB cell-wide settings, specified as a structure containing these parameter fields.

Parameter FieldRequired or OptionalValuesDescription
NDLRBRequired

Scalar integer from 6 to 110

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

NCellIDRequired

Integer from 0 to 503

Physical layer cell identity

CyclicPrefixOptional

'Normal' (default), 'Extended'

Cyclic prefix length

CellRefPRequired

1, 2, 4

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

NSubframeRequired

0 (default), nonnegative scalar integer

Subframe number

The following parameter applies only when chs.EPDCCHStart is absent.

CFIRequired

1, 2, or 3
Scalar or if the CFI varies per subframe, a vector of length 10 (corresponding to a frame).

Control format indicator (CFI) value. In TDD mode, CFI varies per subframe for the RMCs ('R.0', 'R.5', 'R.6', 'R.6-27RB', 'R.12-9RB')

DuplexModeOptional

'FDD' (default), 'TDD'

Duplexing mode, specified as:

• 'FDD' for Frequency Division Duplex or

• 'TDD' for Time Division Duplex

The following parameters apply when DuplexMode is set to 'TDD'.

TDDConfigOptional

0, 1 (default), 2, 3, 4, 5, 6

SSCOptional

0 (default), 1, 2, 3, 4, 5, 6, 7, 8, 9

Special subframe configuration (SSC)

NFrameOptional

0 (default), nonnegative scalar integer

Frame number

CSIRSPeriodOptional

'Off' (default), 'On', Icsi-rs (0,...,154), [Tcsi-rs Dcsi-rs]. You can also specify values in a cell array of configurations for each resource.

CSI-RS subframe configurations for one or more CSI-RS resources. Multiple CSI-RS resources can be configured from a single common subframe configuration or from a cell array of configurations for each resource.

The following CSI-RS resource parameters apply only when CSIRSPeriod sets one or more CSI-RS subframe configurations to any value other than 'Off'. Each parameter length must be equal to the number of CSI-RS resources required.

CSIRSConfigRequired

Nonnegative scalar integer

Array CSI-RS configuration indices. See TS 36.211, Table 6.10.5.2-1.

CSIRefPRequired

1 (default), 2, 4, 8

Array of number of CSI-RS antenna ports

ZeroPowerCSIRSPeriodOptional

'Off' (default), 'On', Icsi-rs (0,...,154), [Tcsi-rs Dcsi-rs]. You can also specify values in a cell array of configurations for each resource.

Zero power CSI-RS subframe configurations for one or more zero power CSI-RS resource configuration index lists. Multiple zero power CSI-RS resource lists can be configured from a single common subframe configuration or from a cell array of configurations for each resource list.

The following zero power CSI-RS resource parameter is only applicable if one or more of the above zero power subframe configurations are set to any value other than 'Off'.

ZeroPowerCSIRSConfigRequired

16-bit bitmap character vector or string scalar (truncated if not 16 bits or '0' MSB extended), or a numeric list of CSI-RS configuration indices. You can also specify values in a cell array of configurations for each resource.

Zero power CSI-RS resource configuration index lists (TS 36.211 Section 6.10.5.2). Specify each list as a 16-bit bitmap character vector or string scalar (if less than 16 bits, then '0' MSB extended), or as a numeric list of CSI-RS configuration indices from TS 36.211 Table 6.10.5.2-1 in the '4' CSI reference signal column. Multiple lists can be defined using a cell array of individual lists.

EPDCCH-specific channel transmission configuration, specified as a structure that can contain the following parameter fields.

Parameter FieldRequired or OptionalValuesDescription
EPDCCHTypeRequired if the EPDCCH type list parameter field is absent

'Localized', 'Distributed'

EPDCCH transmission type

EPDCCHPRBSetRequired if the EPDCCH Type list parameter field is absent

Vector of zero-based indices for the PRB pairs corresponding to the EPDCCH PRB set. The number of PRB pair indices must be a power of 2.

EPDCCH PRB pair indices

EPDCCHFormatRequired

0, 1, 2, 3, or 4

Number of ECCEs per EPDCCH transmission (equivalently the aggregation level L) as required by TS 36.211 Table 6.8A 1–2.

EPDCCHStartOptional

0, 1, 2, 3, or 4

If this parameter is not present, then the cell-wide CFI parameter is used for the starting symbol.

EPDCCH starting symbol

RNTIRequired

0 (default), scalar integer

Radio network temporary identifier (RNTI) value (16 bits)

DCIFormatOptional

'Format0', 'Format1', 'Format1A', 'Format1B', 'Format1C', 'Format1D', 'Format2', 'Format2A', 'Format2B', 'Format2C', 'Format2D', 'Format3', 'Format3A', 'Format4', 'Format5', 'Format5A'

EPDCCHPRBSetListOptional

cell array of one or two vectors

PRB pair indices for one or two EPDCCH sets

EPDCCHTypeListOptional

cell array of one or two arrays

EPDCCH transmission types for one or two EPDCCH sets

## Output Arguments

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EPDCCH ECCE candidate indices, returned as an M-by-2 matrix or a cell array containing 2 M-by-2 matrices. M is the number of EPDCCH candidates monitored for the configuration provided. This variable is defined in TS 36.213 Tables 9.1.4-1a to 9.1.4-5b. Each two-element row of the matrix ind (or the rows of each matrix in cell array ind) contains the inclusive indices of a single EPDCCH candidate location.

• If chs.EPDCCHPRBSetList and chs.EPDCCHTypeList are present and either chs.EPDCCHPRBSet or chs.EPDCCHType are absent, one or two EPDCCH sets are returned in a cell array containing one or two matrices, one for each set.

• If both chs.EPDCCHPRBSet and chs.EPDCCHType are present, only the single candidate matrix which matches the PRB set size and EPDCCH type given by chs.EPDCCHPRBSet and chs.EPDCCHType is returned. This allows the number of candidates M to be correctly calculated for TS 36.213 Tables 9.1.4-3a to 9.1.4-5b (corresponding to two EPDCCH sets) while returning a single set of candidates in matrix form. This format is consistent with the parameterization other EPDCCH-related functions that take CHS.EPDCCHPRBSet and CHS.EPDCCHType as parameters and operate on a single EPDCCH set.

• If chs.EPDCCHPRBSetList is absent, then chs.EPDCCHPRBSet is required, and if chs.EPDCCHTypeList is absent then chs.EPDCCHType is required.

Dimensional information about the EPDCCH search space candidates, returned as a scalar structure containing:

Parameter FieldDescriptionValues
nEPDCCH

Number of REs in a PRB pair configured for possible EPDCCH transmission. See TS 36.211. [1], Section 6.8A.1.

Integer
NECCEPerPRB

Number of ECCE per PRB pair

Integer
NEREGPerECCE

Number of EREG per ECCE

Integer
NECCEPerEPDCCH

Number of ECCES per EPDCCH transmission (equivalently the EPDCCH aggregation level L) as given by TS 36.211 [1] ,Table 6.8A.1-2

Integer
EPDCCHCase

Case number (1,2,3). See TS 36.213 [2], Section 9.1.4

Integer
NECCE

One or two element vector containing the number of ECCE available for transmission of EPDCCHs in the PRB pair set

Integer

Data Types: struct

## References

[1] 3GPP TS 36.211. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation.” 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.