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 1-based linear indexing RE indices given the structure enb. It returns the subframe resource element (RE) indices for the physical downlink control channels (PDCCH). By default, ind is a NRE-by-CellRefP matrix of indices in a 1-based linear indexing style which can directly index elements of a N-by-M-by-CellRefP array representing the subframe grid across CellRefP antenna ports. 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 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 should then be mapped, as described in section 6.8.5 of [1].

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

example

ind = ltePDCCHIndices(enb,exreg,opts) will return a matrix of indices as above where the resources not to be assigned to PDCCH are defined explicitly by vector exreg rather than taken to be the PCFICH and PHICH configured by enb. The exreg must contain valid resource element group (REG) indices but can be either 0 or 1-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)
   452     1

Get PDCCH Indices and Exclude Resources

Explicitly exclude resources when retrieving PDCCH indices.

First, do not exclude any resources. Call the ltePDCCHIndices function and provide an empty matrix for the argument exreg.

enb = lteRMCDL('R.0');
ind = ltePDCCHIndices(enb,[],'re');
size(ind)
   480     1

All RE indices are returned in the required mapping order.

Next, explicitly exclude the PCFICH and PHICH indices.

enb = lteRMCDL('R.0');
exreg = [ltePCFICHIndices(enb,'reg'); ltePHICHIndices(enb,'reg')];
ind = ltePDCCHIndices(enb,exreg,'re');
size(ind)
   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 to 110

Number of downlink (DL) resource blocks (RBs)

NCellIDRequired

Nonnegative scalar integer (0,…,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 1-based or 0-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 0- or 1-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 a numeric matrix of size NRE-by-CellRefP. The matrix contains 1-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.

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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