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ltePSBCHDRSIndices

PSBCH DM-RS resource element indices

Description

ind = ltePSBCHDRSIndices(ue) returns the subframe resource element (RE) indices for the demodulation reference signal (DM-RS) associated with a PSBCH transmission for the specified UE settings structure. By default, the indices are returned in one-based linear indexing form. You can use this form to directly index elements of a matrix representing the subframe resource grid for antenna port 1010. For more information, see PSBCH Demodulation Reference Signal Indexing.

example

ind = ltePSBCHDRSIndices(ue,opts) formats the returned indices using options specified by opts.

Examples

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Write the complex PSBCH DM-RS values into the PSBCH DM-RS resource elements in a synchronization subframe for both D2D and V2X sidelink modes and display an image of their locations.

Create a user equipment settings structure and an empty resource grid subframe for 10 MHz bandwidth and D2D sidelink mode.

ue = struct();
ue.NSLRB = 50;
ue.CyclicPrefixSL = 'Normal';
ue.NSLID = 1;
subframe_D2D = lteSLResourceGrid(ue);

Generate PSBCH DM-RS indices and load PSBCH DM-RS values into subframe.

psbchdrs_indices = ltePSBCHDRSIndices(ue);
subframe_D2D(psbchdrs_indices) = ltePSBCHDRS(ue);

Change user equipment settings to V2X sidelink mode.

ue.SidelinkMode = 'V2X';

Generate the grid subframe, the PSBCH DM-RS indices and load PSBCH DM-RS values into subframe_V2X.

subframe_V2X = lteSLResourceGrid(ue);
psbchdrs_indices = ltePSBCHDRSIndices(ue);
subframe_V2X(psbchdrs_indices) = ltePSBCHDRS(ue);

Display the PSBCH DM-RS locations for both sidelink modes.

subplot(2,1,1);
imagesc(100*abs(subframe_D2D)); 
axis xy; title('D2D');
subplot(2,1,2);
imagesc(100*abs(subframe_V2X)); 
axis xy; title(ue.SidelinkMode);

Figure contains 2 axes objects. Axes object 1 with title D2D contains an object of type image. Axes object 2 with title V2X contains an object of type image.

Input Arguments

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UE equipment settings, specified as a parameter structure containing these fields:

Sidelink mode, specified as 'D2D' or 'V2X'.

Data Types: char | string

Number of sidelink resource blocks, specified as an integer scalar from 6 to 110.

Example: 6, which corresponds to a channel bandwidth of 1.4 MHz.

Data Types: double

Cyclic prefix length, specified as 'Normal' or 'Extended'.

Data Types: char | string

Output format options for resource element indices, specified as a character vector, cell array of character vectors, or string array. For convenience, you can specify several options as a single character vector or string scalar by a space-separated list of values placed inside the quotes. Values for opts when specified as a character vector include (use double quotes for string) :

Category Options Description

Indexing style

'ind' (default)

The returned indices are in linear index style.

'sub'

The returned indices are in [subcarrier,symbol,port] subscript row style.

Index base

'1based' (default)

The returned indices are one-based.

'0based'

The returned indices are zero-based.

Example: 'ind 1based', "ind 1based", {'ind','1based'}, or ["ind","1based"] specify the same formatting options.

Data Types: char | string | cell

Output Arguments

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Resource element indices, returned as an integer column vector or a three-column integer matrix. By default, the indices are returned in a 144-by-1 column vector in one-based linear indexing form. You can use this form to directly access elements of a matrix representing the subframe resource grid for antenna port 1010. For V2X sidelink, the output is a 216-by-1 complex column for the three DM-RS symbols in a subframe. To specify alternative indexing formats, use the opts input argument.

More About

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References

[1] 3GPP TS 36.211. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

Version History

Introduced in R2016b