Documentation

ltePRSIndices

PRS resource element indices

Syntax

  • ind = ltePRSIndices(enb)
  • ind = ltePRSIndices(enb,opts)
    example

Description

ind = ltePRSIndices(enb) returns a column vector of one-based linear indices for the PRS elements in the subframe, given the cell-wide settings parameter structure, enb. The length of ind is the number of resource elements (NRE). It returns the indices for the Positioning Reference Signal (PRS) resource element (RE) locations transmitted on antenna port 6. By default, these indices are in one-based linear indexing form that can directly index elements in a matrix representing a single subframe of the port 6 resource grid. Other index representations can also be created. These indices are ordered as the complex PRS symbols should be mapped and will not include any elements allocated to PBCH, PSS, and SSS. A PRS subframe configuration schedule can be defined as required. If the subframe contains no PRS, ind is an empty vector.

The optional enb.PRSPeriod parameter controls the downlink subframes in which PRS will be present, either always 'On' or 'Off', or defined by the scalar subframe configuration index, Iprs (0,...,2399), or the explicit subframe periodicity and offset pair, [Tprs Dprs], as listed in TS 36.211 [1], Section 6.10.4.3. The PRS containing subframes are located in conjunction with the parameters enb.NSubframe and optional enb.NFrame. NSubframe can be greater than 10; thus, setting NSubframe to 11 is equivalent to setting NSubframe to 1 and NFrame to 1.

example

ind = ltePRSIndices(enb,opts) allows control of the format of the returned indices through a cell array opts of option strings.

Examples

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Generate PRS Resource Element Indices

Generate the PRS resource element (RE) indices for subframe 0 of a 10 MHz downlink.

Create a cell-wide configuration structure initialized for RMC R.2. Configure for full band PRS (NPRSRB = NDLRB). Configure Iprs = 0, which sets [Tprs Dprs] = [160 0].

rmc = lteRMCDL('R.2');
rmc.NPRSRB = rmc.NDLRB;
rmc.PRSPeriod = 0;

Generate PRS indices.

prsIndices = ltePRSIndices(rmc,'ind');
prsIndices(1:4)
ans =

        1804
        1810
        1816
        1822

Input Arguments

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enb — Cell-wide settingsstructure

Cell-wide settings, specified as a structure. enb contains the following fields.

The parameters TDDConfig and SSC are only required if DuplexMode is set to 'TDD'.

NDLRB — Number of downlink resource blocks 6,…,110

Number of downlink resource blocks, specified as a nonnegative scalar integer from 6 through 110.

Example: 50

Data Types: double

CellRefP — Number of cell-specific reference signal antenna ports1 (default) | 2 | 4

Number of cell-specific reference signal antenna ports, specified as 1, 2, or 4.

Example: 1

Data Types: double

NCellID — Physical layer cell identitynonnegative scalar integer

Physical layer cell identity, specified as a nonnegative scalar integer.

Example: 3

Data Types: double

NSubframe — Subframe numbernonnegative scalar integer

Subframe number, specified as a nonnegative scalar integer.

Example: 3

Data Types: double

NFrame — Frame number0 (default) | optional | nonnegative scalar integer

Frame number, specified as a nonnegative scalar integer.

Example: 3

Data Types: double

CyclicPrefix — Cyclic prefix length'Normal' (default) | optional | 'Extended'

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

Data Types: char

DuplexMode — Duplex mode type'FDD' (default) | optional | 'TDD'

Duplex mode type, specified as 'FDD' or 'TDD'.

Data Types: char

TDDConfig — Uplink or downlink configuration for TDD0 (default) | optional | 0,...,6

Uplink or downlink configuration for TDD, specified as a nonnegative scalar integer from 0 through 6. Optional. Required only for 'TDD' duplex mode.

Example: 4

Data Types: double

SSC — Special subframe configuration for TDD0 (default) | optional | 0,...,9

Example: 5

Special subframe configuration for TDD, specified as a nonnegative scalar integer from 0 through 9. Required only for 'TDD' duplex mode.

Data Types: double

NPRSRB — Number of PRS physical resource blocks0,...,NDLRB

Number of PRS physical resource blocks, specified as a nonnegative scalar integer from 0 through NDLRB.

Example: 32

Data Types: double

PRSPeriod — Positioning reference signal (PRS) period'On' (default) | optional | 'Off' | [Iprs] | [Tprs Dprs]

Positioning reference signal (PRS) period, specified as 'On', 'Off', a numeric scalar, or a 1-by-2 vector. This parameter controls the downlink subframes in which PRS will be present. For details, see ltePRSIndices.

Example: 0

Example: [160 0]

Data Types: char | double

opts — Options to control format of returned indicesstring | cell array of strings

Options to control format of returned indices, specified as a string or a cell array of strings. opts can contain the following option strings.

Indexing style — Indexing style of returned indices'ind' (default) | 'sub'

Cell array option, specified as 'ind' or 'sub'. If 'ind', the returned indices are in linear index form. If 'sub', the indices are in [subcarrier, symbol, antenna] subscript form. In this case, ind is a matrix of size NRE-by-3.

Data Types: char

Index base — Index base of returned indices'1based' (default) | '0based'

Index base of returned indices, specified as '1based' or '0based'. This option controls whether the returned indices are one-based or zero-based.

Data Types: char

Data Types: char | cell

Output Arguments

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ind — PRS resource element indicesinteger column vector | integer matrix

PRS resource element indices, returned as an integer column vector of length NRE or an integer matrix of size NRE-by-3. These indices are for the PRS resource element (RE) locations transmitted on antenna port 6.

Example: 1804

Data Types: uint32

References

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

Introduced in R2014a

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