Methods to communicate parameters across multiple component carriers of a carrier aggregation for sidelink communication

1. An apparatus of a User Equipment (UE) configured for sidelink operation in accordance with a carrier aggregation (CA) of a plurality of component carriers (CCs), the apparatus comprising:

one or more processors, configured to:

select one or more CCs of the plurality of CCs for transmission of a sidelink synchronization signal (SLSS) and a physical sidelink broadcast channel (PSBCH);

encode the SLSS for transmission on each of selected CCs in a subframe, wherein the SLSS is for synchronization by other UEs for the sidelink operation;

encode the PSBCH for transmission on the selected CCs in the same subframe used for transmission of the SLSS, wherein the PSBCH is encoded to include a plurality of parameters related to the sidelink operation, wherein the plurality of parameters is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation; and

encode one or more physical sidelink shared channels (PSSCHs) for transmission in accordance with the carrier aggregation, wherein the PSSCHs are encoded for transmission on the plurality of CCs in accordance with the plurality of parameters propagated across the plurality of CCs;

perform transmission on the plurality of CCs in accordance with the plurality of parameters.

2. The apparatus according to claim 1 , wherein the plurality of parameters related to the sidelink operation includes:

a pre-configured bandwidth parameter of the selected CCs,

a pre-configured time-division duplexing (TDD) configuration parameter of the selected CCs,

an in-coverage parameter, and

a direct frame number (DFN) parameter.

3. The apparatus according to claim 2 , wherein the one or more processors are further configured to:

determine timing synchronization for the sidelink operation based on signaling received from a base station; and

derive the in-coverage parameter and the DFN parameter based on the signaling received from the base station.

4. The apparatus according to claim 2 , wherein the one or more processors are further configured to:

receive one or more global navigation satellite system (GNSS) signals;

determine timing synchronization for the sidelink operation based on the one or more GNSS signals; and

determine the DFN parameter based on the determined timing synchronization for the sidelink operation and a pre-configured DFN offset parameter.

5. The apparatus according to claim 2 , wherein the one or more processors are further configured to:

determine timing synchronization for the sidelink operation based on signaling received from another UE; and

determine the DFN parameter based on signaling received from the other UE.

6. The apparatus according to claim 2 , wherein:

the bandwidth parameter indicates a bandwidth in terms of a number of resource blocks (RBs),

the TDD configuration parameter indicates a TDD specific physical channel configuration,

the in-coverage parameter indicates whether the UE is in Evolved Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio Area Network (E-UTRAN) coverage, and

the DFN parameter for the selected CCs indicates a frame number in which the SLSS and SLBCH are transmitted.

7. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

encode a master information block (MIB) for inclusion in the PSBCH, the MIB encoded to include the plurality of parameters related to the sidelink operation.

8. The apparatus according to claim 7 , wherein:

the MIB is a MasterinformationBlock-SL or a MasterInformationBlock-SL-V2X

the plurality of parameters related to the sidelink operation includes:

a pre-configured sl-Bandwidth parameter for the selected CCs,

a pre-configured tdd-config parameter for the selected CCs,

an in-coverage parameter, and

a direct frame number (DFN) parameter.

9. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

encode the PSBCH to include an SLSS identifier (SLSS-ID) that is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation.

10. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

encode the PSBCH to include an indicator of whether the plurality of parameters is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation.

11. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

select the CCs for transmission of the SLSS and the PSBCH based on a tie-breaking rule that is based one or more of:

an SLSS CA indication flag, and

one or more sidelink reference signal received power (SL-RSRP) measurements of the CCs of the plurality of CCs.

12. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

determine if reselection of the CC or transmission of the SLSS and the PSBCH is to be triggered when:

a currently used SLSS is lost at a used CC,

all synchronization sources which provide global navigation satellite system (GNSS) or network timing are lost at the selected CC, or

the UE has not detected an SLSS source at the selected CC.

13. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

periodically reselect one of the CCs of the plurality of CCs for transmission of the SLSS and the PSBCH in accordance with a period,

wherein the period is preconfigured by a network, predefined by a protocol, or determined autonomously based on SLSS detection statistics.

14. The apparatus according to claim 1 , wherein the one or more processors are further configured to:

encode the SLSS for transmission on:

the selected CCs, or

all of the CCs of a set-B that includes the selected CCs.

15. The apparatus according to claim 1 , wherein:

the plurality of CCs includes a synchronization set of CCs,

the processing circuitry further configured to encode the SLSS for transmission in accordance with one of:

selection of a subset of the CCs of the synchronization set, and periodic transmission of the SLSS on the CCs of the subset,

selection of one of the CCs of the synchronization set, and periodic transmission on the selected CC,

cyclic switching across the CCs of the synchronization set, or iterative switching of CC groups.

16. The apparatus according to claim 1 , wherein:

the apparatus includes a transceiver to transmit the SLSS and the PSBCH, and

the one or more processors include a baseband processor to encode the SLSS and the PSBCH.

17. A non-transitory computer-readable storage medium that stores operations for execution by one or more processors of a User Equipment (UE), the UE configured for sidelink operation on a plurality of component carriers (CCs), the operations to configure the one or more processors to:

select one of the plurality of CCs based on one or more sidelink reference signal received powers (SL-RSRPs);

encode, for transmission on the selected CC, a sidelink synchronization signal (SLSS) to enable synchronization of other UEs for the sidelink operation;

encode, for transmission on the selected CC, a physical sidelink broadcast channel (PSBCH) that includes a master information block (MIB),

encode the MIB to include a plurality of parameters related to the sidelink operation, wherein the plurality of parameters is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation; and

encode one or more physical sidelink shared channels (PSSCHs) for transmission in accordance with the carrier aggregation, wherein the PSSCHs are encoded for transmission on the plurality of CCs in accordance with the plurality of parameters propagated across the plurality of CCs.

18. The non-transitory computer-readable storage medium according to claim 17 , wherein the plurality of parameters related to the sidelink operation includes:

a pre-configured bandwidth parameter of the selected CC,

a pre-configured time-division duplexing (TDD) configuration parameter of the selected CC,

an in-coverage parameter,

a direct frame number (DFN) parameter, and

one or more reserved bits.

19. An apparatus of a User Equipment (UE) configured for sidelink operation in accordance with a carrier aggregation (CA) of a plurality of component carriers (CCs), the apparatus comprising:

one or more processors, configured to:

select one of the plurality of CCs;

encode a sidelink synchronization signal (SLSS) for transmission on the selected CC;

encode a physical sidelink broadcast channel (PSBCH) for transmission on the selected CC,

wherein the PSBCH is encoded to include a plurality of parameters related to the sidelink operation, including one or more of: a bandwidth parameter of the selected CC, a time-division duplexing (TDD) configuration parameter of the selected CC, an in-coverage parameter, and a direct frame number (DFN) parameter,

wherein the plurality of parameters is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation; and

encode one or more physical sidelink shared channels (PSSCHs) for transmission in accordance with the carrier aggregation, wherein the PSSCHs are encoded for transmission on the plurality of CCs in accordance with the plurality of parameters propagated across the plurality of CCs.

20. The apparatus according to claim 19 , wherein the one or more processors are further configured to:

encode the PSBCH to include an SLSS identifier (SLSS-ID) that is to be propagated across all of the CCs of the plurality of CCs for the sidelink operation.