Documentation

ltePDCCHIndices

PDCCH resource element indices

Syntax

  • ind = ltePDCCHIndices(enb)
    example
  • ind = ltePDCCHIndices(enb,opts)
  • ind = ltePDCCHIndices(enb,exreg,opts)
    example

Description

example

ind = ltePDCCHIndices(enb) returns a NRE-by-CellRefP matrix of one-based linear indexing RE indices given the structure enb. It returns the subframe resource element (RE) indices for the physical downlink control channels (PDCCH).

The NRE indices returned cover all PDCCH resources in the control region not already assigned to PCFICH or PHICH (see ltePDCCHInfo). They are ordered as the complete block of padded, interleaved, and shifted PDCCH modulation symbols that ready to be mapped, as described in TS 36.211 [1], Section 6.8.5.

ind = ltePDCCHIndices(enb,opts) allows control of the format of the returned indices through a cell array opts.

example

ind = ltePDCCHIndices(enb,exreg,opts) returns a matrix of indices, where the vector exreg explicitly defines resources not to be assigned to PDCCH. The exreg must contain valid resource element group (REG) indices but can be either zero-based or one-based throughout, and indices which do not fall within the control region are ignored.

Examples

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Get PDCCH Resource Element Indices

Retrieve PDCCH resource element (RE) indices.

Create an RMC R.0 configuration structure and find its PDCCH RE indices. Display the size of the indices.

enb = lteRMCDL('R.0');
ind = ltePDCCHIndices(enb);
size(ind)
ans =

   452     1

Get PDCCH Indices and Exclude Resources

Explicitly exclude resources when retrieving PDCCH indices.

Create a cell-wide configuration structure initalized for RMC R.0. Generate RE indices for the PDCCH providing an empty matrix for the argument exreg so that no resources are excluded.

enb = lteRMCDL('R.0');
ind = ltePDCCHIndices(enb,[],'re');
numPDCCHwithNoExclusion = size(ind)
numPDCCHwithNoExclusion =

   480     1

All RE indices are returned in the required mapping order.

Explicitly exclude the PCFICH and PHICH indices.

enb = lteRMCDL('R.0');
exreg = [ltePCFICHIndices(enb,'reg'); ltePHICHIndices(enb,'reg')];
ind = ltePDCCHIndices(enb,exreg,'re');
numPDCCHwithExclusion = size(ind)
numPDCCHwithExclusion =

   452     1

This call returns the same result as the default syntax call, ltePDCCHIndices(enb).

Input Arguments

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enb — Cell-wide settingsstructure

enb is a structure having the following fields.

Parameter FieldRequired or OptionalValuesDescription
NDLRBRequired

Integer within the range (6,...,110)

Number of downlink (DL) resource blocks (RBs)

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

CFIRequired

1, 2, or 3

Control format indicator value

NgRequired

'Sixth', 'Half', 'One', 'Two'

HICH group multiplier

PHICHDurationOptional

'Normal' (default), 'Extended'

PHICH duration

DuplexModeOptional

'FDD' (default), 'TDD'

Duplexing mode, specified as:

  • 'FDD' for Frequency Division Duplex or

  • 'TDD' for Time Division Duplex

The following field is required when DuplexMode is set to 'TDD'.
TDDConfigOptional

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

Uplink or downlink configuration

NSubframeRequired

Integer greater than 0

Subframe number.

Data Types: struct

opts — Option strings for symbol formattingstring | cell array of strings

Option strings for symbol formatting, specified as a string or a cell array of strings. opts can contain the following option strings.

Indexing unit — Format of the returned indices're' (default) | 'reg'

Format of the returned indices, specified as a string. This parameter indicates that the returned values correspond to either individual resource elements (REs) or resource element groups (REGs).

Data Types: char

Indexing style — Style of the returned indices'ind' (default) | 'sub'

Style of the returned indices, specified as a string. This parameter indicates the style of returned indices as either linear index form or [subcarrier, symbol, antenna] subscript row form.

Data Types: char

Index base — Index base of the returned indices'1based' (default) | '0based'

Index base of the returned indices, specified as a string. This parameter indicates the index base of returned indices as either one-based or zero-based.

Data Types: char

Data Types: char | cell

exreg — Resources excluded from PDCCHvector

Resources excluded from PDCCH, specified as a vector. This vector explicitly defines those resources not to be assigned to PDCCH. exreg must contain valid resource element group (REG) indices but can be either zero-based or one-based throughout. Indices which do not fall within the control region are ignored.

Data Types: double

Output Arguments

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ind — PDCCH RE indicesnumeric matrix

PDCCH RE indices, returned as an NRE-by-CellRefP numeric matrix by default. The matrix contains one-based linear indexing RE indices. Each column of ind identifies the same set of NRE subframe resource elements but with indices offset to select them in a different antenna "page" of the 3-D resource array.

The default matrix of indices in a one-based linear indexing style which can directly index elements of an M-by-N-by-CellRefP array, where M is the number of symbols, and N is the number of subcarriers representing the subframe grid across CellRefP antenna ports.

Data Types: double

References

[1] 3GPP TS 36.211. "Physical Channels and Modulation." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA). URL: http://www.3gpp.org.

Introduced in R2014a

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