nrPRACHIndices

R2026b

Generate PRACH resource element indices

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Syntax

[ind,info] = nrPRACHIndices(carrier,prach)
[ind,info] = nrPRACHIndices(carrier,prach,Name=Value)

Description

[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.

example

[ind,info] = nrPRACHIndices(carrier,prach,Name=Value) specifies output formatting options using one or more name-value arguments. For example, IndexStyle="subscript" specifies the indexing form of the output.

Examples

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Open Live Script

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. The function uses only these properties of this input.

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: IndexStyle="subscript" specifies the indexing form of the output.

RE indexing form, specified as 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

RE indexing base, specified as one of these values:

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

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

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

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C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Version History

Introduced in R2020a

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See Also

Functions

Objects