Method and device for transmitting and receiving synchronization signal of device-to-device communication terminal in wireless communication system

A second User Equipment (UE) device comprising:

• at least one processor;
• and
• at least one computer memory operatively coupled to the at least one processor and storing instructions which, when executed, cause the at least one processor to perform operations,
• wherein the operations include:
• receiving, from a first UE directly synchronized to a Global Navigation Satellite System (GNSS), a first sidelink synchronization signal (SLSS) with first SLSS ID,
• selecting a second SLSS ID for a second SLSS based on the received first SLSS;
• and
• transmitting the second SLSS,
• wherein, based on the first UE is out of a cell coverage and the first SLSS is received on a first resource, a first value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID, and
• wherein, based on the first UE is in the cell coverage and the first SLSS is received on a second resource, a second value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID.

A processing device configured to operate in a wireless communication system, the processing device comprising:

• at least one processor;
• and
• at least one memory operatively connected to the at least one processor and storing at least one instructions that, when executed by the at least one processor, causes the at least one processor to perform operations comprising:
• receiving, from a first UE directly synchronized to a Global Navigation Satellite System (GNSS), a first sidelink synchronization signal (SLSS) with a first SLSS ID,
• selecting a second SLSS ID for a second SLSS based on the received first SLSS;
• and
• transmitting the second SLSS,
• wherein, based on the first UE is out of a cell coverage and the first SLSS is received on a first resource, a first value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID, and
• wherein, based on the first UE is in the cell coverage and the first SLSS is received on a second resource, a second value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID.

A non-transitory computer-readable storage medium storing at least one computer program including instructions which, when executed by at least one processor, cause the at least one processor to perform operations for a second user equipment (UE),

• wherein the operations include:
• receiving, from a first UE directly synchronized to a Global Navigation Satellite System (GNSS), a first sidelink synchronization signal (SLSS) with a first SLSS ID,
• selecting a second SLSS ID for a second SLSS based on the received first SLSS;
• and
• transmitting the second SLSS,
• wherein, based on the first UE is out of a cell coverage and the first SLSS is received on a first resource, a first value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID, and
• wherein, based on the first UE is in the cell coverage and the first SLSS is received on a second resource, a second value related to GNSS-synchronization propagation through the out of the cell coverage is selected as the second SLSS ID.