Method and apparatus for transmitting signal in wireless communication system

A method for operating a first terminal in a wireless communication system, the method comprising:

• transmitting, by the first terminal, a synchronization signal block (SSB) to a second terminal;
• receiving a response message including a time difference value;
• transmitting control information based on a physical sidelink control channel (PSCCH);
• and
• transmitting data based on a physical sidelink shared channel (PSSCH),
• wherein the SSB includes sidelink synchronization signal (SLSS) and physical broadcast channel (PBCH),
• wherein the response message includes a time difference value that is calculated based on the SSB,
• wherein the SSB is an SSB with a low priority based on a synchronization source, and
• wherein transmission timing of the response message is determined based on the time difference value and a number of SSBs received by the second terminal.

A terminal in a wireless communication system, comprising:

• a transceiver;
• and
• a processor coupled with the transceiver,
• wherein the processor controls:
• the transceiver to receive at least one or more synchronization signal blocks (SSBs),
• the terminal to select an SSB among the at least one or more SSBs based on a priority order,
• the transceiver to transmit a response message including a time difference value,
• the transceiver to receive sidelink synchronization signal (SLSS) and physical broadcast channel (PBCH) based on the at least one or more SSBs;
• the transceiver to receive control information based on a physical sidelink control channel (PSCCH);
• and
• the transceiver to receive data based on a physical sidelink shared channel (PSSCH),
• wherein the time difference value is calculated based on the selected SSB,
• wherein the selected SSB is an SSB with a high priority based on a synchronization source, and
• wherein transmission timing of the response message is determined based on the time difference value and a number of received SSBs.

A first terminal in a wireless communication system, comprising:

• a transceiver;
• and
• a processor coupled with the transceiver,
• wherein the processor controls the transceiver to:
• transmit a synchronization signal block (SSB) to a second terminal,
• receive a response message including a time difference value,
• transmit control information based on a physical sidelink control channel (PSCCH), and
• transmit data based on a physical sidelink shared channel (PSSCH),
• wherein the SSB includes sidelink synchronization signal (SLSS) and physical broadcast channel (PBCH),
• wherein the response message includes a time difference value that is calculated based on the SSB,
• wherein the SSB is an SSB with a low priority based on a synchronization source, and
• wherein transmission timing of the response message is determined based on the time difference value and a number of SSBs received by the second terminal.

A device comprising at least one memory and at least processor functionally coupled with the at least one memory,

• wherein the at least one processor controls the device to:
• receive at least one or more synchronization signal blocks (SSBs),
• select an SSB among the at least one or more SSBs based on a priority order,
• transmit a response message including a time difference value,
• receive sidelink synchronization signal (SLSS) and physical broadcast channel (PBCH) based on the at least one or more SSBs;
• receive control information based on a physical sidelink control channel (PSCCH), and
• receive data based on a physical sidelink shared channel (PSSCH),
• wherein the time difference value is calculated based on the selected SSB,
• wherein the selected SSB is an SSB with a high priority based on a synchronization source, and
• wherein transmission timing of the response message is determined based on the time difference value and a number of received SSBs.

A non-transitory computer-readable medium storing at least one instruction, comprising the at least one instruction that is executable by a processor,

• wherein the at least one instruction instructs the computer-readable medium to:
• receive at least one or more synchronization signal blocks (SSBs),
• select an SSB among the at least one or more SSBs based on a priority order, and
• transmit a response message including a time difference value,
• receive sidelink synchronization signal (SLSS) and physical broadcast channel (PBCH) based on the at least one or more SSBs;
• receive control information based on a physical sidelink control channel (PSCCH);
• and
• receive data based on a physical sidelink shared channel (PSSCH),
• wherein the time difference value is calculated based on the selected SSB,
• wherein the selected SSB is an SSB with a high priority based on a synchronization source, and
• wherein transmission timing of the response message is determined based on the time difference value and a number of received SSBs.