nrPDCCHResources

Generate PDCCH and PDCCH DM-RS resources

Since R2020a

Syntax

ind = nrPDCCHResources(carrier,pdcch)

[ind,dmrsSym,dmrsInd] = nrPDCCHResources(carrier,pdcch)

[ind,dmrsSym,dmrsInd] = nrPDCCHResources(carrier,pdcch,Name,Value)

Description

ind = nrPDCCHResources(carrier,pdcch) returns physical downlink control channel (PDCCH) resource element indices ind, as defined in TS 38.211 Section 7.3.2 [1]. The input carrier specifies carrier configuration parameters for a specific OFDM numerology. The input pdcch specifies PDCCH configuration parameters.

[ind,dmrsSym,dmrsInd] = nrPDCCHResources(carrier,pdcch) also returns PDCCH demodulation reference signal (DM-RS) symbols dmrsSym and PDCCH DM-RS resource element indices dmrsInd, as defined in TS 38.211 Section 7.4.1.3.

[ind,dmrsSym,dmrsInd] = nrPDCCHResources(carrier,pdcch,Name,Value) specifies output formatting options using one or more name-value pair arguments.

Examples

Generate and Map PDCCH Symbols to Carrier Grid

Configure the carrier and the PDCCH with default configuration parameters.

carrier = nrCarrierConfig;
pdcch = nrPDCCHConfig;

Generate PDCCH symbols for a random DCI codeword by using PDCCH configuration parameters for scrambling and identifying the UE.

dciCW = randi([0 1],864,1);
sym = nrPDCCH(dciCW,pdcch.DMRSScramblingID,pdcch.RNTI);

Generate PDCCH resource element indices by using the specified carrier and PDCCH objects.

ind = nrPDCCHResources(carrier,pdcch);

Create a grid for mapping PDCCH symbols to the grid.

cgrid = zeros(12*carrier.NSizeGrid,carrier.SymbolsPerSlot);

Map PDCCH symbols to the grid.

cgrid(ind) = sym;

Generate PDCCH DM-RS Symbols and Indices

Configure the carrier with default configuration parameters.

carrier = nrCarrierConfig;

Configure the CORESET with 6 frequency resources, a duration of 3 OFDM symbols, and a REG bundle size of 3.

crst = nrCORESETConfig;
crst.FrequencyResources = ones(1,6);
crst.Duration = 3;
crst.REGBundleSize = 3;

Configure the PDCCH with the specified bandwidth part and CORESET.

pdcch = nrPDCCHConfig;
pdcch.NStartBWP = 6;
pdcch.NSizeBWP = 36;
pdcch.CORESET = crst;
pdcch.AggregationLevel = 16;

Generate PDCCH DM-RS symbols and indices for the specified carrier and PDCCH.

[~,dmrs,dmrsInd] = nrPDCCHResources(carrier,pdcch);

Generate PDCCH and DM-RS Indices Relative to BWP Grid

Configure a carrier grid of 60 resource blocks (RBs), where the starting RB index relative to the common resource block 0 (CRB 0) is 3.

carrier = nrCarrierConfig;
carrier.NStartGrid = 3;
carrier.NSizeGrid = 60;

Configure noninterleaved CORESET with 6 frequency resources and a duration of 3 OFDM symbols.

crst = nrCORESETConfig;
crst.FrequencyResources = ones(1,6);
crst.Duration = 3;
crst.CCEREGMapping = 'noninterleaved';

Configure the PDCCH with the specified bandwidth part and CORESET.

pdcch = nrPDCCHConfig;
pdcch.NStartBWP = 5;
pdcch.NSizeBWP = 48;
pdcch.CORESET = crst;
pdcch.AggregationLevel = 16;

Generate PDCCH resource element indices and DM-RS symbol indices using 1-based, subscript indexing form relative to the BWP grid.

[ind,~,dmrsInd] = nrPDCCHResources(carrier,pdcch,...
    'IndexOrientation','bwp','IndexStyle','subscript');

Input Arguments

carrier — Carrier configuration parameters

nrCarrierConfig object

Carrier configuration parameters for a specific OFDM numerology, specified as an nrCarrierConfig object.

pdcch — PDCCH configuration parameters

nrPDCCHConfig object

PDCCH configuration parameters, specified as an nrPDCCHConfig object.

Name-Value Arguments

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.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'IndexStyle','subscript','IndexBase','0based' specifies the indexing form and indexing base of the output.

IndexStyle — RE indexing form

'index' (default) | 'subscript'

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

IndexBase — RE indexing base

'1based' (default) | '0based'

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

IndexOrientation — Indexing orientation of PDCCH and DM-RS resource elements

'carrier' (default) | 'bwp'

Indexing orientation of PDCCH and DM-RS resource elements, specified as the comma-separated pair consisting of 'IndexOrientation' and one of these values:

• 'carrier' — Indices are referenced with respect to the carrier grid.

• 'bwp' — Indices are referenced with respect to the bandwidth part.

Data Types: char | string

OutputDataType — Data type of PDCCH DM-RS symbols

'double' (default) | 'single'

Data type of PDCCH DM-RS symbols, specified as the comma-separated pair consisting of 'OutputDataType' and one of these values:

• 'double' — Output symbols are of double data type.

• 'single' — Output symbols are of single data type.

Data Types: char | string

Output Arguments

ind — PDCCH resource element indices

M-by-1 vector (default) | M-by-3 matrix

PDCCH 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 aggregation level of the PDCCH and is equal to pdcch.AggregationLevel × 6 × 12 × 3 / 4.

Depending on the value of 'IndexBase', the indices are either 1-based or 0-based.

Data Types: uint32

dmrsSym — DM-RS symbols

N-by-1 complex vector

DM-RS symbols, returned as an N-by-1 complex vector. N depends on the aggregation level of the PDCCH and is equal to pdcch.AggregationLevel × 6 × 12 × 1 / 4.

Data Types: single | double

dmrsInd — DM-RS resource element indices

N-by-1 vector (default) | N-by-3 matrix

DM-RS resource element indices, returned as one of these values:

• N-by-1 vector — When 'IndexStyle' is set to 'index'.

• N-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.

N depends on the aggregation level of the PDCCH and is equal to pdcch.AggregationLevel × 6 × 12 × 1 / 4.

Depending on the value of 'IndexBase', the indices are either 1-based or 0-based.

Data Types: uint32

References

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

[2] 3GPP TS 38.213. “NR; Physical layer procedures for control.” 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 'OutputDataType' name-value argument must be compile-time constant for code generation. For example, when you call the function with 'OutputDataType','single', 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

R2023a: C/C++ code generation updates

For C/C++ code generation, the limitation to specify 'IndexStyle', 'IndexBase', or 'IndexOrientation' name-value arguments as compile-time constants has been removed.

R2020b: DM-RS reference point update for CORESET ID 0

Starting in R2020b, the reference point for the DM-RS sequence-to-subcarrier resource mapping for CORESET ID 0 is the lowest physical resource block of the CORESET instead of CRB 0. This update affects the resources that you generate with this function for CORESET ID 0. For all other CORESET ID values, the reference point remains CRB0.