nrPUSCHDMRS

Generate PUSCH DM-RS symbols

Syntax

sym = nrPUSCHDMRS(carrier,pusch)

sym = nrPUSCHDMRS(carrier,pusch,'OutputDataType',datatype)

Description

sym = nrPUSCHDMRS(carrier,pusch) returns a matrix containing demodulation reference signal (DM-RS) symbols of physical uplink shared channel (PUSCH), as defined in TS 38.211 Section 6.4.1.1.1 [1]. carrier specifies the carrier configuration parameters for a specific OFDM numerology. pusch specifies the PUSCH configuration parameters.

sym = nrPUSCHDMRS(carrier,pusch,'OutputDataType',datatype) specifies the data type for the DM-RS symbols.

Examples

Generate PUSCH DM-RS Symbols for CP-OFDM

Create a carrier configuration object with default properties. This object corresponds to a 10 MHz carrier with 15 kHz subcarrier spacing.

carrier = nrCarrierConfig;

Create a physical uplink shared channel (PUSCH) configuration object with specified properties. When transform precoding is set to 0, the waveform type is cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM).

pusch = nrPUSCHConfig;
pusch.TransformPrecoding = 0;
pusch.TransmissionScheme = 'codebook';
pusch.NumAntennaPorts = 4;
pusch.TPMI = 0;

Configure PUSCH demodulation reference signal (DM-RS) with specified parameters.

pusch.DMRS.DMRSAdditionalPosition = 1;
pusch.DMRS.DMRSTypeAPosition = 2;
pusch.DMRS.DMRSPortSet = 2;
pusch.DMRS.NIDNSCID = 10;
pusch.DMRS.NSCID = 1;

Generate DM-RS symbols associated with PUSCH of single data type.

sym = nrPUSCHDMRS(carrier,pusch,'OutputDataType','single')

sym = 624×4 single matrix

  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 + 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 + 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 + 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 + 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
  -0.3536 - 0.3536i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
      ⋮

Generate PUSCH DM-RS Symbols and Indices

Create a carrier configuration with 30 kHz subcarrier spacing and 5 MHz transmission bandwidth.

carrier = nrCarrierConfig;
carrier.SubcarrierSpacing = 30;
carrier.NSizeGrid = 11;

Create a physical uplink shared channel (PUSCH) configuration object with specified properties. When transform precoding is set to 1, the waveform type is discrete fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM).

pusch = nrPUSCHConfig;
pusch.NSizeBWP = 9;
pusch.NStartBWP = 1;
pusch.PRBSet = 0:3;
pusch.TransformPrecoding = 1;
pusch.FrequencyHopping = 'intraSlot';
pusch.SecondHopStartPRB = 5;

Create a PUSCH demodulation reference signal (DM-RS) object with specified properties.

dmrs = nrPUSCHDMRSConfig;
dmrs.DMRSAdditionalPosition = 1;
dmrs.DMRSTypeAPosition = 2;
dmrs.DMRSPortSet = 3;
dmrs.GroupHopping = 1;
dmrs.SequenceHopping = 0;
dmrs.NRSID = 10;

Assign the PUSCH DM-RS configuration object to DMRS property of PUSCH configuration object.

pusch.DMRS = dmrs;

Generate PUSCH DM-RS symbols and indices for the specified carrier, PUSCH configuration, and output formatting name-value pair argument.

sym = nrPUSCHDMRS(carrier,pusch,'OutputDataType','single')

sym = 96×1 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
  -0.7071 - 0.7071i
  -0.7071 + 0.7071i
  -0.7071 - 0.7071i
   0.7071 + 0.7071i
  -0.7071 - 0.7071i
      ⋮

ind = nrPUSCHDMRSIndices(carrier,pusch,'IndexBase','0based','IndexOrientation','bwp')

ind = 96×1 uint32 column vector

   217
   219
   221
   223
   225
   227
   229
   231
   233
   235
   237
   239
   241
   243
   245
      ⋮

Create a bandwidth part (BWP) grid, and then map the DM-RS symbols on the grid.

bwp = complex(zeros([pusch.NSizeBWP*12 carrier.SymbolsPerSlot pusch.NumLayers]));
bwp(ind+1) = sym; % Map the DM-RS symbols

Map the BWP to the carrier resource grid, and then display the carrier grid.

grid = complex(zeros([carrier.NSizeGrid*12 carrier.SymbolsPerSlot pusch.NumLayers])); % Create carrier resource grid
offset = pusch.NStartBWP-carrier.NStartGrid; % BWP start location in the carrier grid
grid(offset*12+1:(offset+pusch.NSizeBWP)*12,:,:) = bwp;
imagesc(abs(grid(:,:,1)));
axis xy;
xlabel('OFDM Symbols');
ylabel('Subcarriers');
title('PUSCH DM-RS Resource Elements in the Carrier Resource Grid');

Input Arguments

carrier — Carrier configuration parameters

nrCarrierConfig object

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

• NCellID

• SubcarrierSpacing

• CyclicPrefix

• NSizeGrid

• NStartGrid

• NSlot

• IntraCellGuardBands

pusch — PUSCH configuration parameters

nrPUSCHConfig object

PUSCH configuration parameters, specified as an nrPUSCHConfig object. This function uses only these properties of the nrPUSCHConfig object.

• NSizeBWP

• NStartBWP

• Modulation

• NumLayers

• MappingType

• SymbolAllocation

• PRBSet

• TransformPrecoding

• TransmissionScheme

• NumAntennaPorts

• TPMI

• CodebookType (since R2024a)

• FrequencyHopping

• SecondHopStartPRB

• Interlacing

• RBSetIndex

• InterlaceIndex

• DMRS

For operation with shared spectrum channel access for frequency range 1 (FR1), set the Interlacing property to true, then use the RBSetIndex and InterlaceIndex object properties to specify the allocated frequency resources. (since R2023b)

datatype — Data type for generated DM-RS symbols

'double' (default) | 'single'

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

Data Types: char | string

Output Arguments

sym — DM-RS symbols

complex matrix

DM-RS symbols, returned as a complex matrix. The number of columns correspond to the number of antenna ports configured.

Data Types: single | double
Complex Number Support: Yes

References

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

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

The datatype input argument must be compile-time constant. For example, when specifying 'single' as the output data type, include {coder.Constant('OutputDataType'),coder.Constant('single')} in the -args value of the codegen function. For more information, see the coder.Constant (MATLAB Coder) class.

Version History

Introduced in R2020a

R2024a: Release 18 support for eight antenna ports, up to eight layers, and two codewords

The Modulation, NumLayers, NumAntennaPorts, TPMI, and CodebookType object properties of the pusch input add support to eight antenna ports, up to eight layers, and two codewords in PUSCH transmissions.

R2023b: Configure intracell guard bands

Use the IntraCellGuardBands object property of the carrier input to specify intracell guard bands.

R2023b: Support for release 16 interlacing for operation in unlicensed spectrum (NR-U)

Use the Interlacing, RBSetIndex, and InterlaceIndex properties of the pusch input argument to configure interlaced PUSCH transmissions.