Method for terminal executing V2X communication to determine transmission power in wireless communication system and terminal utilizing the method

1. A method for performing vehicle-to-everything (V2X) communication in a wireless communication system, the method performed by a terminal and comprising:

determining transmission power for the V2X communication; and

transmitting a V2X signal to another terminal at the transmission power,

wherein the transmission power for the V2X transmission is determined by using a second parameter set independent of a first parameter set used when the terminal transmits a signal to a base station (BS),

wherein a first path loss included in the first parameter set is calculated based on a cell-specific reference signal (CRS) transmitted from the BS,

wherein a second path loss included in the second parameter set is calculated based on a synchronization signal transmitted from the another terminal, not the CRS transmitted from the BS, even when the terminal is located in a coverage area of the BS,

wherein when the V2X signal is transmitted on a second carrier, synchronization of the V2X signal transmitted on the second carrier is performed based on a synchronization signal received, from the another terminal, on a first carrier which is different from the second carrier, and

wherein when the terminal transmits the V2X signal on a second carrier, the terminal further transmits a message indicating that the terminal cannot perform a V2X reception on a third carrier which is contiguous with the second carrier.

2. The method of claim 1 , wherein the another terminal is a road side unit (RSU).

3. The method of claim 2 ,

wherein the second parameter set comprises at least one of a path loss, an open-loop parameter, a power offset value, and a maximum transmission power, and

wherein the transmission power for the V2X transmission is determined based on the second parameter set.

4. The method of claim 2 , wherein when the terminal receives a synchronization signal or a reference signal from a plurality of RSUs, an RSU which has transmitted a synchronization signal or reference signal having a greatest reception strength is selected as the another terminal.

5. The method of claim 2 , wherein a path loss, used to determine the transmission power for the V2X transmission, is estimated based on a synchronization signal or a reference signal received from the RSU.

6. The method of claim 2 , wherein a power offset value, used to determine the transmission power for the V2X transmission, is calculated based on a number of resource blocks allocated to the V2X transmission.

7. The method of claim 1 , wherein the terminal is a terminal located in a first vehicle, and the another terminal is a terminal located in a second vehicle.

8. The method of claim 7 , wherein the second parameter set comprises at least one of a path loss, an open-loop parameter, a power offset value, and a maximum transmission power, and

wherein the transmission power for the V2X transmission is determined based on the second parameter set.

9. The method of claim 7 , wherein a path loss, used to determine the transmission power for the V2X transmission, is estimated on the basis of a synchronization signal or reference signal received from the another terminal.

10. The method of claim 7 , wherein a power offset value, used to determine the transmission power for the V2X transmission, is calculated based on a number of resource blocks allocated to the V2X transmission.

11. The method of claim 7 , wherein when transmitting a V2X signal having a different quality of service (QoS) or a latency requirement, the transmission power is determined by applying a parameter set determined according to the QoS or the latency requirement.

12. A terminal comprising:

a transmitter and a receiver; and

a processor, operatively coupled to the transmitter and the receiver, wherein the processor is configured to:

determine a transmission power for the V2X communication;

control the transmitter to transmit a V2X signal to another terminal at the transmission power,

wherein the transmission power for the V2X transmission is determined by using a second parameter set independent of a first parameter set used when the terminal transmits a signal to a base station (BS),

wherein a first path loss included in the first parameter set is calculated based on a cell-specific reference signal (CRS) transmitted from the BS,

wherein a second path loss included in the second parameter set is calculated based on a synchronization signal transmitted from the another terminal, not the CRS transmitted from the BS, even when the terminal is located in coverage of the BS,

wherein when the V2X signal is transmitted on a second carrier, synchronization of the V2X signal transmitted on the second carrier is performed based on a synchronization signal received, from the another terminal, on a first carrier which is different from the second carrier, and

wherein when the terminal transmits the V2X signal on a second carrier, the terminal further transmits a message indicating that the terminal cannot perform a V2X reception on a third carrier which is contiguous with the second carrier.