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

collapse all

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

collapse all

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, base, and unit of generated indices, specified as one of these forms.

  • 'format base unit'

  • "format base unit"

  • {'format','base','unit'}

  • ["format","base","unit"]

Where format, base, and unit are defined in this table.

OptionValuesDescription
format'ind' (default), 'sub'

Output format of generated indices

To return the indices as a column vector, specify this option as 'ind'.

To return the indices as an NRE-by-3 matrix, where NRE is the number of REs, specify this option as 'sub'. Each row of the matrix contains the subcarrier, symbol, and antenna port as its first, second, and third element, respectively.

base'1based' (default), '0based'

Index base

To generate indices whose first value is 1, specify this option as '1based'. To generate indices whose first value is 0, specify this option as '0based'.

unit're' (default), 'reg'

Unit of returned indices

To indicate that the returned values correspond to individual resource elements (REs), specify this option as 're'. To indicate that the returned values correspond to resource element groups (REGs), specify this option as 'reg'.

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

Data Types: char | string | cell

Output Arguments

collapse all

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