ltePHICHIndices

PHICH resource element indices

Syntax

ind = ltePHICHIndices(enb)

ind = ltePHICHIndices(enb,opts)

Description

ind = ltePHICHIndices(enb) returns the subframe resource element (RE) indices, ind, for the Physical Hybrid-ARQ Indicator Channels (PHICH), given the parameter fields of cell-wide settings structure, enb. By default, the number of rows of ind is the number of resource elements (N_RE), and ind is an N_RE-by-CellRefP matrix of indices in a one-based linear indexing style. These indices can directly index elements of an N-by-M-by-CellRefP array that represents the subframe resource grid across CellRefP antenna ports. Each column of ind identifies the same set of N_RE resource elements, but with indices offset to select them in a different antenna “page” of the 3-D resource array.

The indices returned are for all PHICH groups in a subframe, where the number of groups depends on the bandwidth and PHICH Ng parameter. See ltePHICHInfo for details. The indices are ordered as the modulation symbols should be mapped for the set of consecutive PHICH groups. The PHICH resources are normally all assigned in the first OFDM symbol of a subframe, unless the PHICH duration is of the extended type.

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

Examples

Generate PHICH Indices

Generate PHICH resource element (RE) indices in linear form and resource element group (REG) indices in subscript form.

Get one-based PHICH resource element (RE) indices in linear form.

enb = lteRMCDL('R.14');
enb.NDLRB = 6;
indOneBased = ltePHICHIndices(enb,{'ind','re'})

indOneBased = 12x4 uint32 matrix

      8   1016   2024   3032
      9   1017   2025   3033
     11   1019   2027   3035
     12   1020   2028   3036
     26   1034   2042   3050
     27   1035   2043   3051
     29   1037   2045   3053
     30   1038   2046   3054
     50   1058   2066   3074
     51   1059   2067   3075
      ⋮

Get zero-based PHICH resource element group (REG) indices in subscript form, where each column of ind corresponds to a dimension of the 3-D resource grid array: subcarrier, OFDM symbol, and antenna port.

indZeroBased = ltePHICHIndices(enb,{'0based','sub','reg'})

indZeroBased = 12x3 uint32 matrix

    6    0    0
   24    0    0
   48    0    0
    6    0    1
   24    0    1
   48    0    1
    6    0    2
   24    0    2
   48    0    2
    6    0    3
      ⋮

Input Arguments

enb — Cell-wide settings

scalar structure

Cell-wide settings, specified as a scalar structure. enb can contain the following fields. The TDDConfig and NSubframe parameter fields are only required if DuplexMode is set to 'TDD'.

NDLRB — Number of downlink resource blocks

positive integer

Number of downlink resource blocks, specified as a positive integer.

Data Types: double

NCellID — Physical layer cell identity

nonnegative integer

Physical layer cell identity, specified as a nonnegative integer.

Data Types: double

CyclicPrefix — Cyclic prefix length

'Normal' (default) | optional | 'Extended'

Cyclic prefix length, specified as 'Normal' or 'Extended'.

Data Types: char | string

CellRefP — Number of cell-specific reference signal antenna ports

1 | 2 | 4

Number of cell-specific reference signal antenna ports, specified as 1, 2, or 4.

Data Types: double

Ng — HICH group multiplier

'Sixth' | 'Half' | 'One' | 'Two'

HICH group multiplier, specified as 'Sixth', 'Half', 'One', or 'Two'.

Data Types: char | string

PHICHDuration — PHICH duration

'Normal' (default) | optional | 'Extended'

PHICH duration, specified as 'Normal' or 'Extended'.

Data Types: char | string

DuplexMode — Duplex mode

'FDD' (default) | optional | 'TDD'

Duplex mode, specified as 'FDD' or 'TDD'.

Data Types: char | string

TDDConfig — Uplink or downlink configuration

0 (default) | optional | 1 | 2 | 3 | 4 | 5 | 6

Uplink or downlink configuration, specified as a nonnegative scalar integer from 0 through 6. Only required if DuplexMode is set to 'TDD'.

Data Types: double

NSubframe — Subframe number

nonnegative integer

Subframe number, specified as a nonnegative integer. Only required if DuplexMode is set to 'TDD'.

Data Types: double

Data Types: struct

opts — Output format, base, and unit of generated indices

character vector | string scalar | cell array of character vectors | string array

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.

Option	Values	Description
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

ind — PHICH resource element indices

numeric matrix

PHICH resource element indices, returned as a numeric matrix. The size of the matrix is N_RE-by-CellRefP. By default, it contains one-based linear indexing RE indices.

Data Types: uint32

Version History

Introduced in R2014a