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Generate PDSCH PT-RS symbols



sym = nrPDSCHPTRS(carrier,pdsch) returns sym, which contains phase tracking reference signal (PT-RS) symbols of the physical downlink shared channel (PDSCH), as defined in TS 38.211 Section [1]. carrier specifies the carrier configuration parameters for a specific OFDM numerology and pdsch specifies the PDSCH configuration parameters.

sym = nrPDSCHPTRS(carrier,pdsch,'OutputDataType',datatype) specifies the data type of the output PT-RS symbols.


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Create a carrier configuration object with default properties. This object corresponds to a 10 MHz carrier.

carrier = nrCarrierConfig;

Create a default PDSCH configuration object, and then enable the PT-RS configuration.

pdsch = nrPDSCHConfig;
pdsch.EnablePTRS = 1;

Create a PDSCH phase tracking reference signal (PT-RS) configuration object with specified properties.

ptrs = nrPDSCHPTRSConfig;
ptrs.TimeDensity = 2;
ptrs.FrequencyDensity = 4;
ptrs.REOffset = '10';

Assign the PDSCH PT-RS configuration object to PTRS property of PDSCH configuration object.

pdsch.PTRS = ptrs;

Generate PDSCH PT-RS symbols of data type single.

sym = nrPDSCHPTRS(carrier,pdsch,'OutputDataType','single')
sym = 78x1 single column vector

  -0.7071 - 0.7071i
  -0.7071 - 0.7071i
   0.7071 - 0.7071i
   0.7071 - 0.7071i
   0.7071 - 0.7071i
  -0.7071 - 0.7071i
  -0.7071 + 0.7071i
  -0.7071 - 0.7071i
  -0.7071 + 0.7071i
   0.7071 + 0.7071i

Generate PDSCH PT-RS indices in subscript form and set the index orientation to bandwidth part.

ind = nrPDSCHPTRSIndices(carrier,pdsch,'IndexStyle','subscript','IndexOrientation','bwp')
ind = 78x3 uint32 matrix

    19     1     1
    67     1     1
   115     1     1
   163     1     1
   211     1     1
   259     1     1
   307     1     1
   355     1     1
   403     1     1
   451     1     1

Input Arguments

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Carrier configuration parameters for a specific OFDM numerology, specified as an nrCarrierConfig object. This function uses only these properties of the nrCarrierConfig object.

PDSCH configuration parameters, specified as an nrPDSCHConfig object. This function only uses these nrPDSCHConfig object properties.

Property FieldValuesDescription

[] (default), integer from 1 to 275

Size of the bandwidth part (BWP) in terms of number of physical resource blocks (PRBs). The default value of [] implies that the value is equal to NSizeGrid of carrier input argument.


[] (default), integer from 0 to 2473

Starting PRB index of BWP relative to CRB 0. The default value of [] implies that the value is equal to NStartGrid of carrier input argument.


nrPDSCHReservedConfig (default), cell array of nrPDSCHReservedConfig objects

Reserved PRBs and OFDM symbols pattern in BWP, specified as a cell array of objects, of class nrPDSCHReservedConfig.


[] (default), nonnegative integer vector

Reserved resource elements (RE) indices within the BWP


1 (default), integer from 1 to 8

Number of transmission layers. For one codeword, use an integer between 1 to 4. For two codewords, use an integer between 5 to 8.


'A' (default), 'B'

Mapping type of PDSCH


[0 14] (default), two-element vector of nonnegative integers

OFDM symbols allocated for PDSCH


[0:51] (default), vector of nonnegative integer from 0 to 274

PRBs allocated for PDSCH within the BWP


1 (default), integer from 0 to 65,535

Radio network temporary identifier of the user equipment


nrPDSCHDMRSConfig configuration object

DMRS configuration object only uses these properties.

  • DMRSConfigurationType

  • DMRSReferencePoint

  • DMRSTypeAPosition

  • DMRSLength

  • DMRSAdditionalPosition

  • CustomSymbolSet

  • DMRSPortSet



For more information, see nrPDSCHDMRSConfig.


0 (default), 1

PT-RS configuration, specified as one of these values.

  • 0 — Disable PT-RS configuration.

  • 1 — Enable PT-RS configuration.


nrPDSCHPTRSConfig configuration object

PDSCH PT-RS configuration, specified as a nrPDSCHPTRSConfig configuration object.

Data type for the generated PT-RS symbols, specified as 'double' or 'single'.

Data Types: char | string

Output Arguments

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PT-RS symbols, returned as a complex column vector.

Data Types: double | single
Complex Number Support: Yes


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

Extended Capabilities

Introduced in R2020a