Generation of synchronization signal for sidelink communication
According to an embodiment of the present disclosure, provided is a method by which a first device performs SL communication. The method may comprise the steps of: generating S-SSB including symbols for S-PSS, symbols for S-SSS, and symbols for PSBCH; and transmitting the S-SSB to a second device, wherein a total number of symbols for S-PSS is three, and the symbols for S-PSS include a first S-PSS symbol, a second S-PSS symbol, and a third S-PSS symbol.
1. A method for performing, by a first apparatus, sidelink (SL) communication, the method comprising:
generating a sidelink synchronization signal block (S-SSB) including symbols related to a sidelink primary synchronization signal (S-PSS), symbols related to sidelink secondary synchronization signal (S-SSS) and symbols related to a physical sidelink broadcast channel (PSBCH);
transmitting the S-SSB to a second apparatus;
obtaining synchronization based on the S-SSB;
transmitting, to a second apparatus, sidelink control information (SCI) for scheduling a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH); and
transmitting, to the second apparatus, the PSSCH,
wherein the total number of the S-PSS symbols is 3,
wherein the S-PSS symbols include a first S-PSS symbol, a second S-PSS symbol and a third S-PSS symbol,
wherein a first S-PSS sequence for the first S-PSS symbol is generated based on the same sequence polynomial as a Uu-PSS sequence for a Uu-PSS symbol, the same initial value as the Uu-PSS sequence and a cyclic shift (CS) different from the Uu-PSS sequence,
wherein a second S-PSS sequence for the second S-PSS symbol is generated based on a sequence polynomial identical to a second m-sequence among a first m-sequence and the second m-sequence used to generate a gold sequence for a Uu-SSS symbol or an S-SSS symbol, a same initial value as the second m-sequence and a different CS from the second m-sequence, and
wherein the third S-PSS symbol is the first S-PSS symbol complex conjugated in the time domain.
2. The method of claim 1 , wherein the first S-PSS sequence, the second S-PSS sequence and a third S-PSS sequence for the third S-PSS symbol are different from each other.
3. The method of claim 1 , wherein the total number of the S-SSS symbols is 2.
4. The method of claim 1 , wherein maximum power reduction (MPR) of one S-PSS symbol among the S-PSS symbols, MPR of one S-SSS symbol among the S-SSS symbols and MPR of one PSBCH symbol among the PSBCH symbols are the same.
5. The method of claim 4 , wherein the following symbol adjacent to the last S-PSS symbol on time resources among the S-PSS symbols is the first S-SSS symbol on time resources among the S-SSS symbols.
6. The method of claim 5 , wherein among the S-PSS symbols, a preceding symbol adjacent to the first S-PSS symbol on time resources is an automatic gain control (AGC) symbol.
7. The method of claim 6 , wherein the AGC symbol is the first symbol on the time resources of the S-SSB, the S-PSS symbols include a second symbol, a third symbol and a fourth symbol on the time resources of the S-SSB, the first S-SSS symbol is the fifth symbol on the time resources of the S-SSB.
8. The method of claim 1 , wherein the first S-PSS symbol is derived based on a first correlator that performs a multiplication operation based on a multiplier and performs a plurality of addition and subtraction operations,
wherein the third S-PSS symbol is derived based on a second correlator that performs a multiplication operation based on the multiplier and performs a plurality of addition and subtraction operations.
9. The method of claim 8 , wherein in some of the plurality of addition and subtraction operations performed by the first correlator, a subtraction operation is replaced by an addition operation, or an addition operation is replaced by a subtraction operation, in the process of deriving the third S-PSS symbol based on the second correlator.
10. A first apparatus for performing sidelink (SL) communication, the first apparatus comprising:
one or more memories storing instructions;
one or more transceivers; and
one or more processors connected to the one or more memories and the one or more transceivers, wherein the one or more processors:
generate a sidelink synchronization signal block (S-SSB) including symbols related to a sidelink primary synchronization signal (S-PSS), symbols related to sidelink secondary synchronization signal (S-SSS) and symbols related to a physical sidelink broadcast channel (PSBCH);
control the one or more transceivers to transmit the S-SSB to a second apparatus;
obtain synchronization based on the S-SSB;
control the one or more transceivers to transmit, to a second apparatus, sidelink control information (SCI) for scheduling a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH); and
control the one or more transceivers to transmit, to the second apparatus, the PSSCH,
wherein the total number of the S-PSS symbols is 3,
wherein the S-PSS symbols include a first S-PSS symbol, a second S-PSS symbol and a third S-PSS symbol,
wherein a first S-PSS sequence for the first S-PSS symbol is generated based on the same sequence polynomial as a Uu-PSS sequence for a Uu-PSS symbol, the same initial value as the Uu-PSS sequence and a cyclic shift (CS) different from the Uu-PSS sequence,
wherein a second S-PSS sequence for the second S-PSS symbol is generated based on a sequence polynomial identical to a second m-sequence among a first m-sequence and the second m-sequence used to generate a gold sequence for a Uu-SSS symbol or an S-SSS symbol, a same initial value as the second m-sequence and a different CS from the second m-sequence, and
wherein the third S-PSS symbol is the first S-PSS symbol complex conjugated in the time domain.
11. The first apparatus of claim 10 , wherein the first S-PSS sequence, the second S-PSS sequence and a third S-PSS sequence for the third S-PSS symbol are different from each other.
12. An apparatus configured to control a first user equipment (UE), the apparatus comprising:
one or more processors; and
one or more memories operably connectable to the one or more processors and storing instructions, wherein the one or more processors execute the instructions to:
generate a sidelink synchronization signal block (S-SSB) including symbols related to a sidelink primary synchronization signal (S-PSS), symbols related to sidelink secondary synchronization signal (S-SSS) and symbols related to a physical sidelink broadcast channel (PSBCH);
transmit the S-SSB to a second apparatus;
obtain synchronization based on the S-SSB;
transmit, to a second apparatus, sidelink control information (SCI) for scheduling a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH); and
transmit, to the second apparatus, the PSSCH,
wherein the total number of the S-PSS symbols is 3,
wherein the S-PSS symbols include a first S-PSS symbol, a second S-PSS symbol and a third S-PSS symbol,
wherein a first S-PSS sequence for the first S-PSS symbol is generated based on the same sequence polynomial as a Uu-PSS sequence for a Uu-PSS symbol, the same initial value as the Uu-PSS sequence and a cyclic shift (CS) different from the Uu-PSS sequence,
wherein a second S-PSS sequence for the second S-PSS symbol is generated based on a sequence polynomial identical to a second m-sequence among a first m-sequence and the second m-sequence used to generate a gold sequence for a Uu-SSS symbol or an S-SSS symbol, a same initial value as the second m-sequence and a different CS from the second m-sequence, and
wherein the third S-PSS symbol is the first S-PSS symbol complex conjugated in the time domain.