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nrPRACHIndices

Generate PRACH resource element indices

Description

example

[ind,info] = nrPRACHIndices(carrier,prach) returns resource element indices ind for the physical random access channel (PRACH), as defined in TS 38.211 Section 5.3.2 [1]. The input carrier specifies carrier configuration parameters for a specific OFDM numerology. The input prach specifies PRACH configuration parameters. The function also returns the structure info, which contains carrier-dependent information about the PRACH.

[ind,info] = nrPRACHIndices(carrier,prach,Name,Value) specifies output formatting options using one or more name-value pair arguments.

Examples

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Configure the PRACH and the carrier with default properties.

carrier = nrCarrierConfig;
prach = nrPRACHConfig;

Generate PRACH symbols and indices using the specified carrier and PRACH configuration parameters.

prachSym = nrPRACH(carrier,prach);
prachInd = nrPRACHIndices(carrier,prach);

Generate a PRACH resource grid of all zeros.

prachGrid = nrPRACHGrid(carrier,prach);

Map the PRACH symbols to the PRACH resource grid by using the indices.

prachGrid(prachInd) = prachSym;

Input Arguments

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Carrier configuration parameters for a specific OFDM numerology, specified as an nrCarrierConfig object.

PRACH configuration parameters, specified as an nrPRACHConfig object.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'IndexStyle','subscript','IndexBase','0based' specifies the indexing form and indexing base of the output.

Resource element indexing form, specified as the comma-separated pair consisting of 'IndexStyle' and one of these values:

  • 'index' — The indices are in linear index form.

  • 'subscript' — The indices are in [subcarrier, symbol, antenna] subscript row form.

Data Types: char | string

Resource element indexing base, specified as the comma-separated pair consisting of 'IndexBase' and one of these values:

  • '1based' — The index counting starts from one.

  • '0based' — The index counting starts from zero.

Data Types: char | string

Output Arguments

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PRACH resource element indices, returned as one of these values.

  • M-by-1 vector — When 'IndexStyle' is set to 'index'.

  • M-by-3 matrix — When 'IndexStyle' is set to 'subscript'. The matrix rows correspond to the [subcarrier, symbol, antenna] subscripts based on the number of subcarriers, OFDM symbols, and number of antennas, respectively.

M depends on the length of the Zadoff-Chu preamble sequence and is equal to prach.LRA.

Depending on 'IndexBase', the indices are either 1-based or 0-based.

Data Types: uint32

Carrier-dependent PRACH information, returned as a structure containing one field.

FieldDescription
PRBSetPhysical resource block (PRB) indices occupied by the PRACH preamble for the PUSCH (0-based)

References

[1] 3GPP TS 38.211. “NR; Physical channels and modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

Extended Capabilities

See Also

Functions

Objects

Introduced in R2020a