Method and device for transmitting and receiving signal in wireless communication system
A method and device for transmitting and receiving a signal in a wireless communication system, according to one embodiment of the present invention, comprises transmitting a physical random access channel (PRACH) and receiving a random access response (RAR) on the basis of the PRACH, wherein the PRACH is transmitted via one random access channel (RACH) occasion (RO) of ROs in a RACH slot, timing gap durations exist between the ROs, and the same timing gap durations can be set even if a PRACH format and/or a subcarrier spacing (SCS) used for the PRACH are changed.
1. A method for a user equipment (UE) to transmit and receive signals in a wireless communication system, the method comprising:
transmitting a physical random access channel (PRACH) on one RACH occasion (RO) from among a plurality of ROs included in a random access channel (RACH) slot; and
receiving a random access response (RAR) based on the PRACH,
wherein a time gap is configured between the plurality of ROs, and
wherein the time gap is determined based on a start time point of a first RO among the plurality of ROs and a start time point of a second RO among the plurality of ROs.
2. The method according to claim 1 , wherein the time gap is determined in units of orthogonal frequency division multiplexing (OFDM) symbols.
3. The method according to claim 1 , wherein the transmitting the PRACH comprises:
randomly selecting a backoff counter value based on a contention window size;
reducing the backoff counter value incrementally based on information about an unlicensed band (U-band) that is in an idle state; and
transmitting the PRACH on the one RO based on information indicating that the backoff counter value reaches zero ‘0’,
wherein:
after the backoff counter value reaches ‘1’, the backoff counter value is reduced to zero ‘0’ based on the U-band being in the idle state during a predetermined time located just before the one RO, and
after the backoff counter value reaches ‘1’, the backoff counter value is kept at ‘1’ based on the U-band being in a busy state during a predetermined time located just before the one RO.
4. A user equipment (UE) configured to transmit and receive signals in a wireless communication system, the UE comprising:
at least one transceiver;
at least one processor; and
at least one memory operatively connected to the at least one processor, and configured to store instructions such that the at least one processor performs specific operations by executing the instructions,
wherein the operations comprise:
transmitting a physical random access channel (PRACH) on one RACH occasion (RO) from among a plurality of ROs included in a random access channel (RACH) slot; and
receiving a random access response (RAR) based on the PRACH,
wherein a time gap is configured between the plurality of ROs, and
wherein the time gap is determined based on a start time point of a first RO among the plurality of ROs and a start time point of a second RO among the plurality of ROs.
5. The UE according to claim 4 , wherein the time gap is determined in units of orthogonal frequency division multiplexing (OFDM) symbols.
6. The UE according to claim 4 , wherein the transmitting the PRACH comprises:
randomly selecting a backoff counter value based on a contention window size;
reducing the backoff counter value incrementally based on information about an unlicensed band (U-band) that is in an idle state; and
transmitting the PRACH on the one RO based on information indicating that the backoff counter value reaches zero ‘0’,
wherein:
after the backoff counter value reaches ‘1’, the backoff counter value is reduced to zero ‘0’ based on the U-band being in the idle state during a predetermined time located just before the one RO, and
after the backoff counter value reaches ‘1’, the backoff counter value is kept at ‘1’ based on the U-band being in a busy state during a predetermined time located just before the one RO.
7. A device configured to operate for a user equipment (UE), the device comprising:
at least one processor; and
at least one memory operatively connected to the at least one processor, and configured to store instructions such that the at least one processor performs specific operations by executing the instructions,
wherein the specific operations include:
transmitting a physical random access channel (PRACH) on one RACH occasion (RO) from among a plurality of ROs included in a random access channel (RACH) slot; and
receiving a random access response (RAR) based on the PRACH,
wherein a time gap is configured between the plurality of ROs, and
wherein the time gap is determined based on a start time point of a first RO among the plurality of ROs and a start time point of a second RO among the plurality of ROs.
8. The device according to claim 7 , wherein the time gap is determined in units of orthogonal frequency division multiplexing (OFDM) symbols.
9. The device according to claim 7 , wherein the transmitting the PRACH comprises:
randomly selecting a backoff counter value based on a contention window size;
reducing the backoff counter value incrementally based on information about an unlicensed band (U-band) that is in an idle state; and
transmitting the PRACH on the one RO based on information indicating that the backoff counter value reaches zero ‘0’,
wherein:
after the backoff counter value reaches ‘1’, the backoff counter value is reduced to zero ‘0’ based on the U-band being in the idle state during a predetermined time located just before the one RO, and
after the backoff counter value reaches ‘1’, the backoff counter value is kept at ‘1’ based on the U-band being in a busy state during a predetermined time located just before the one RO.