ltePDCCHDeinterleave

PDCCH deinterleaving and cyclic shifting

Syntax

out = ltePDCCHDeinterleave(enb,in)

Description

example

out = ltePDCCHDeinterleave(enb,in) performs the PDCCH Resource Element Groups (REGs) deinterleaving and cyclic shifting on PDCCH complex modulated symbols, in given cell-wide configuration structure, enb This function performs the inverse of the processing described in TS 36.211 [1], Section 6.8.5.

The cyclic shifting process is the reverse of the NCellID dependent cyclic shift carried out during PDCCH coding to avoid intercell interference. The de-interleaving is performed to reverse the permutation operation described in TS 36.212 [2], Section 5.1.4.2.1 with the exception that “symbol quadruplets” replace “bits”.

Examples

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Perform PDCCH resource element group (REG) deinterleaving. A vector of PDCCH symbols is first interleaved. The output is then deinterleaved and compared with the input vector. Note that instead of actual PDCCH symbols, a range of values from 1 to NRE are used to highlight the interleaved order.

Create a cell-wide configuration structure initialized for RMC R.0. Instead of actual PDCCH symbols, a range of values from 1 to NRE are used to highlight the interleaved order. Interleave the PDCCH symbols, pdcchSym.

enb = lteRMCDL('R.0');
pdcchInfo = ltePDCCHInfo(enb);
pdcchSym = (1:pdcchInfo.NRE).';
startingSymbolOrder = pdcchSym(1:4)
startingSymbolOrder = 4x1 uint64 column vector

   1
   2
   3
   4

interleavedSym = ltePDCCHInterleave(enb,pdcchSym);
interleavedSymbolOrder = interleavedSym(1:4)
interleavedSymbolOrder = 4x1 uint64 column vector

   73
   74
   75
   76

Deinterleave symbols and view the first four.

deinterleavedSym = ltePDCCHDeinterleave(enb,interleavedSym);
deinterleavedSymbolOrder = deinterleavedSym(1:4)
deinterleavedSymbolOrder = 4x1 uint64 column vector

   1
   2
   3
   4

Confirm deinterleaved symbol vector matches the input symbol vector.

isequal(pdcchSym,deinterleavedSym)
ans = logical
   1

Input Arguments

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Cell-wide settings, specified as a scalar structure. enb can contain the following fields.

Physical layer cell identity, specified as an integer from 0 to 503.

Data Types: struct

PDCCH complex modulated input symbols, specified as an NS-by-NTX numeric matrix. NS is the number of modulated symbols, and NTX is the number of transmit antennas. The NS modulated symbols specified in input matrix in must be a concatenation of symbol quadruplets. If the input in is a vector, it deinterleaves the elements of the vector. If in is a matrix, it deinterleaves the rows.

Data Types: double
Complex Number Support: Yes

Output Arguments

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Deinterleaved output, returned as a numeric column vector.

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.

[2] 3GPP TS 36.212. “Multiplexing and channel coding.” 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