ltePCFICHIndices

PCFICH resource element indices

Description

ind = ltePCFICHIndices(enb) returns the 16-by-CellRefP matrix of subframe resource element (RE) indices for the physical control format indicator channel (PCFICH), given the enb input structure. By default, the indices are returned in 1-based linear indexing form that directly indexes elements of a 3-D array representing the subframe resource grid for CellRefP antenna ports. Each column of ind contains per-antenna indices for 16 resource elements in one of the CellRefP array planes. The rows are ordered as the PCFICH modulation symbols should be mapped. The indices can also be returned in a number of alternative indexing formats.

The PCFICH is always transmitted on 16 resource elements, or 4 resource element groups (REG), in the first OFDM symbol of a subframe however their locations depend on the NCellID and NDLRB parameters.

example

ind = ltePCFICHIndices(enb,opts) formats the returned indices using options specified by opts.

Examples

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This example generates physical CFI channel (PCFICH) resource element (RE) indices for two different physical layer cell identity values.

To show the effects of the physical layer cell identity, NCellID, on the indices, first set it to 0. Generate and display the PCFICH indices.

enb.NDLRB = 50;
enb.NCellID = 0;
enb.CyclicPrefix = 'Normal';
enb.CellRefP = 1;
ind = ltePCFICHIndices(enb,{'0based','reg'});
disp(ind)
     0
   150
   300
   450

Next, set the physical layer cell identity, NCellID, to 1. Regenerate and display the PCFICH indices.

enb.NCellID = 1;
ind = ltePCFICHIndices(enb,{'0based','reg'});
disp(ind)
     6
   156
   306
   456

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. (NRBDL)

NCellIDRequired

Integer from 0 to 503

Physical layer cell identity

CyclicPrefixOptional

'Normal' (default), 'Extended'

Cyclic prefix length

CellRefPOptional

1 (default), 2, 4

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

Output format and index base of generated indices, specified as a character vector, a cell array of character vectors, or a string array. You can specify these options as a single character vector or string scalar by a space-separated list of values placed inside quotation marks. This field can contain any of these values:

OptionValuesDescription
Output format'ind' (default), 'sub'Output format of generated indices, specified as 'ind' or 'sub'. The function returns the indices as a column vector when you specify 'ind'. The function returns the indices as an NRE-by-3 matrix when you specify 'sub', where NRE is the number of resource elements. Each row of the matrix contains the subcarrier, symbol, and antenna port as its first, second, and third entries, respectively.
Index base'1based' (default), '0based'Index base, specified as '1based' or '0based'. To generate indices whose first value is 1, specify '1based'. To generate indices whose first value is 0, specify '0based'.
Indexing unit're' (default), 'reg'Unit of the returned indices specified as 're' or 'reg'. To indicate that the returned values correspond to individual resource elements (REs), specify 're'. To indicate that the returned values correspond to resource element groups (REGs), specify 'reg'.

Example: 'ind 0based', "ind 0based", {'ind','0based'}, and ["ind","0based"] specify the same output options.

Data Types: char | string | cell

Output Arguments

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Subframe PCFICH RE indices, returned as a numeric matrix of size 16-by-CellRefP. Each column of ind contains per-antenna indices for 16 resource elements in one of the CellRefP array planes. The rows are ordered as the PCFICH modulation symbols should be mapped.

Introduced in R2014a