Physical sidelink shared channel
a complex symbol column vector containing the physical sidelink shared
channel (PSSCH) for the specified UE settings structure and codeword
bits. Channel processing performed by the function includes PSSCH-specific
scrambling, QPSK or 16-QAM modulation, and SC-FDMA transform precoding,
as defined in TS 36.211 ,
sym = ltePSSCH(
For more information, see Physical Sidelink Shared Channel Processing.
Create PSSCH Symbols
Create a codeword using the SL-SCH transport channel and encode the bits on the PSSCH.
Initialize a UE settings structure. Specify the codeword length to use for the SL-SCH. Choose a length that is a multiple of 12 symbols for normal cyclic prefix and has 4 bits per symbol for 16-QAM modulation. Pick a standard number of resource blocks, such as 10.
ue = struct('CyclicPrefixSL','Normal'); ue.RV = 0; ue.Modulation = '16QAM'; ue.NSAID = 255; ue.NSubframePSSCH = 0; ue.SidelinkMode = 'D2D'; codewordlength = 5760; % (12 symbols)(4 bps)(12 REperRB)(10 PRB)
Create a codeword using the
lteSLSCH function and encode the bits on the PSSCH. Plot the constellation to show the effects of the SC-FDMA precoding on the 16-QAM modulation symbols.
codeword = lteSLSCH(ue,codewordlength,zeros(100,1)); symbols = ltePSSCH(ue,codeword); plot(symbols,'o')
ue — User equipment settings
User equipment settings, specified as a parameter structure containing these fields:
cw — PSSCH codeword
PSSCH codeword, specified as an Mbit-by-1 integer vector. Mbit is the number of bits transmitted on the physical sidelink shared channel in one subframe and must be a multiple of 12. For more information, see Physical Sidelink Shared Channel Processing.
Physical Sidelink Shared Channel Processing
Physical sidelink shared channel (PSSCH) processing includes PSSCH-specific scrambling, QPSK or 16-QAM modulation, and SC-FDMA transform precoding. PSSCH processing follows the processing steps used for PUSCH, with variations defined in TS 36.211, Section 9.3.
For PSSCH, the input codeword length is Mbits = NRE × Nbps, where Nbps is the number of bits per symbol. PSSCH modulation is either QPSK (2 bits per symbol) or 16 QAM (4 bits per symbol).
The number of PSSCH resource elements (NRE) in a subframe is NRE = NPRB × NREperPRB × NSYM and includes symbols associated with the sidelink SC-FDMA guard symbol.
NPRB is the number of physical resource blocks (PRB) used for transmission.
NREperPRB is the number of resource elements in a PRB. Each PRB has 12 resource elements.
NSYM is the number of SC-FDMA symbols in a PSSCH subframe, including symbols associated with the sidelink SC-FDMA guard symbol. The number of SC-FDMA symbols in a PSSCH subframe is 12 for D2D normal cyclic prefix or 10 for D2D extended cyclic prefix and V2X.
info structure output by
ltePSSCHIndices provides Mbits and NRE as
The scrambling sequence generator is initialized with at the start of every PSSCH subframe. For D2D sidelink, is the destination identity (
NSAID) obtained from the
sidelink shared channel. For V2X, is the V2X scrambling identity (
NXID). is the subframe number in the PSSCH subframe pool
deduce the number of resource blocks allocated for SC-FDMA precoding
Physical Sidelink Shared Channel Indexing
and the corresponding
function to populate the PSSCH subframe resource grid. The PSSCH is
transmitted in the available SC-FDMA symbols in a PSSCH subframe,
using a single layer on antenna port 1000. It excludes each symbol
per slot assigned to PSSCH DM-RS. For more information on PSSCH DM-RS,
The indices are ordered as the PSSCH modulation symbols should be
mapped, applying frequency-first mapping. The resource elements in
the last SC-FDMA symbol within a subframe are counted in the mapping
process but should not be transmitted. The sidelink-specific SC-FDMA
modulation creates this guard symbol. For more information on mapping
symbols to the resource element grid, see Resource Grid Indexing.
 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.