V2X operation method performed by terminal in wireless communication system and terminal using same method
The present invention provides a device-to-device (D2D) operation method performed by a tenninal in a wireless communication system, the method comprising: determining whether a transmission time point of a first message having a high priority overlaps a transmission time point of a second message having a priority lower than that of the first message; and transmitting the second message using transmission power lower than transmission power of the first message on the basis of the determination, wherein the transmission of the second message is configured to repeat a predetermined number of times.
1. A method for device-to-device (D2D) operation in a wireless communication system, the method performed by a user equipment (UE) and comprising:
determining whether a transmission time point of a first message having a high priority overlaps a transmission time point of a second message having a low priority;
performing a transmission of the second message based on transmission power lower than transmission power of the first message, based on the determining,
wherein the transmission of the second message is configured to repeat a predetermined number of transmission times,
wherein, when the transmission time point of the first message overlaps the transmission time point of the second message, the second message is transmitted at a greater number of transmission times than the predetermined number of transmission times,
wherein a value of the greater number of transmission times varies depending on a degree at which a value of the transmission power allocated to the transmission of the second message decreases, and
wherein the value of the greater number of transmission times increases as the value of the transmission power allocated to the transmission of the second message decreases.
2. The method of claim 1 , wherein when a decrease in value of the transmission power allocated to the transmission of the second message is not temporary, differences between an existing value of the transmission power allocated to the transmission of the second message and other values of the transmission power allocated to the transmission of the second message are accumulated and the value of the greater number of transmission times varies depending on the accumulated values.
3. The method of claim 1 , further comprising:
transmitting, to the base station, information informing that the second message is transmitted at the greater number of transmission times than the predetermined number of transmission times.
4. The method of claim 1 , wherein transmission power having a relatively large value is used for the transmission of the second message, which relates to a remaining number of transmission times other than the greater number of transmission times of the second message using the transmission power lower than the transmission power of the first message in the predetermined number of transmission times, when the transmission time point of the first message overlaps with the transmission time point of the second message.
5. The method of claim 4 , wherein a predetermined offset is applied to the transmission of the second message, which relates to the remaining number of transmission times.
6. The method of claim 4 , wherein the transmission of the second message, which relates to the remaining number of transmission times is performed in a dedicated resource pool.
7. The method of claim 1 , wherein the first message is a wide area network (WAN) uplink message and the second message is a D2D message.
8. The method of claim 1 , wherein the first message is a D2D synchronization message and the second message is a D2D communication message.
9. The method of claim 1 ,
wherein when the transmission time point of the first message overlaps the transmission time point of the second message, the transmission time point of the first message and the transmission time point of the second message overlap with each other in a frequency division multiplexing (FDM) form in one carrier or the transmission time point of the first message and the transmission time point of the second message overlap with each other in different carriers.
10. The method of claim 1 , wherein the D2D operation is a vehicle to X (V2X) operation.
11. A user equipment (UE) comprising:
a radio frequency (RF) transceiver transmitting and receiving a radio signal; and
a processor operated in association with the RF transceiver,
wherein the processor is configured to:
determine whether a transmission time point of a first message having a high priority overlaps a transmission time point of a second message having a low priority; and
perform a transmission of the second message based on transmission power lower than transmission power of the first message, based on the determine,
wherein the transmission of the second message is configured to repeat a predetermined number of transmission times,
wherein, when the transmission time point of the first message overlaps the transmission time point of the second message, the second message is transmitted at a greater number of transmission times than the predetermined number of transmission times,
wherein a value of the greater number of transmission times varies depending on a degree at which a value of the transmission power allocated to the transmission of the second message decreases, and
wherein the value of the greater number of transmission times increases as the value of the transmission power allocated to the transmission of the second message decreases.