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nrPUSCHDMRS

Generate PUSCH DM-RS symbols

Description

example

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.

example

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

Examples

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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 = 624x4 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
      ⋮

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 = 96x1 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
      ⋮

ind = nrPUSCHDMRSIndices(carrier,pusch,'IndexBase','0based','IndexOrientation','bwp')
ind = 96x1 uint32 column vector

   217
   219
   221
   223
   225
   227
   229
   231
   233
   235
      ⋮

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');

Figure contains an axes object. The axes object with title PUSCH DM-RS Resource Elements in the Carrier Resource Grid contains an object of type image.

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.

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

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

Data Types: char | string

Output Arguments

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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

Version History

Introduced in R2020a