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Generate PRACH resource grid

Since R2020a



grid = nrPRACHGrid(carrier,prach) returns the physical random access channel (PRACH) resource grid for one antenna. The input carrier specifies carrier configuration parameters for a specific OFDM numerology. The input prach specifies PRACH configuration parameters.

grid = nrPRACHGrid(carrier,prach,p) returns the PRACH resource grid for p antennas.

grid = nrPRACHGrid(___,'OutputDataType',datatype) specifies the resource grid symbol data type in addition to the input arguments in any of the previous syntaxes.


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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. The function uses only these properties of this input.

Number of antennas, specified as a positive integer.

Data type of the output symbols, specified as 'double' or 'single'.

Data Types: char | string

Output Arguments

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PRACH resource grid, returned as a K-by-L or K-by-L-by-p complex array of all zeros.

  • K is equal to (carrier.SubcarrierSpacing / prach.SubcarrierSpacing) × carrier.NSizeGrid × 12

  • L is the number of OFDM symbols and depends on the PRACH format.

    • For long formats, L = prach.PRACHDuration.

    • For short format C0, L = 7.

    • For all other short formats, L = 14.

      For more information on PRACH preamble formats, see TS 38.211 Tables and

Data Types: double | single


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

Extended Capabilities

Version History

Introduced in R2020a

See Also