Method and apparatus for performing communication in wireless communication system
A method and an apparatus for performing communication in wireless communication system are provided. The method includes receiving random access channel (RACH) configuration information from a base station (BS), in case that a type of a random access is identified as 2-step contention free based on the RACH configuration information, selecting a synchronization signal block (SSB) with synchronization signal-reference signal received power (SS-RSRP) above a configured threshold among SSBs, identifying a random access occasion corresponding to the selected SSB, identifying a physical uplink shared channel (PUSCH) occasion corresponding to a RACH slot of the selected random access occasion from PUSCH occasions configured based on PUSCH resource configuration information included in the RACH configuration information, and performing msgA transmission based on the identified random access occasion and the identified PUSCH occasion.
1. A user equipment (UE), the UE comprising:
a transceiver; and
a processor configured to:
receive, via the transceiver, random access channel (RACH) configuration information including CFRA-SSB-Resource information and msgA-PUSCH-Resource-CFRA information from a base station (BS), wherein the msgA-PUSCH-Resource-CFRA information includes at least one physical uplink shared channel (PUSCH) occasion, each PUSCH occasion is indexed, and wherein the CFRA-SSB-Resource information includes PUSCH occasion index information indicating an indexed PUSCH occasion,
in case that a type of a random access is identified as 2-step contention free random access (CFRA) based on the RACH configuration information, select a synchronization signal block (SSB) with synchronization signal-reference signal received power (SS-RSRP) above a configured threshold among SSBs,
identify a random access occasion corresponding to the selected SSB,
identify a PUSCH occasion from among the at least one PUSCH occasion configured in the msgA-PUSCH-Resource-CFRA information, according to the PUSCH occasion index information corresponding to the selected SSB, and
perform a message A transmission based on the identified random access occasion and the identified PUSCH occasion.
2. The UE of claim 1 , wherein the msgA-PUSCH-Resource-CFRA information includes parameters regarding:
a modulation coding scheme (MCS) for the message A transmission,
a number of slots containing the at least one PUSCH occasion,
a number of time domain PUSCH occasions in each RACH slot,
a time offset with respect to a start of each RACH slot,
a start symbol and length of the PUSCH occasion,
a guard period between the at least one PUSCH occasion in a unit of symbols,
a resource block (RB)-level guard band between the at least one PUSCH occasion in a frequency domain,
an offset of a lowest PUSCH occasion in the frequency domain,
a number of RBs per PUSCH occasion,
a number of PUSCH occasions in the frequency domain in one time instance, and
a demodulation reference signal (DMRS) configuration for the at least one PUSCH occasion.
3. The UE of claim 1 , wherein at least one PUSCH occasion index is sequentially indexed and is mapped to the at least one PUSCH occasion corresponding to a RACH slot of the identified random access occasion.
4. The UE of claim 3 , wherein the at least one PUSCH occasion corresponding to the RACH slot is indexed by ordering:
firstly, in increasing order of frequency resource indexes for frequency multiplexed PUSCH occasions,
secondly, in increasing order of DMRS resource indexes within the PUSCH occasion, where a DMRS resource index is determined first in an ascending order of a DMRS port index and then in an ascending order of a DMRS sequence index,
thirdly, in increasing order of time resource indexes for time multiplexed PUSCH occasions within a PUSCH slot, and
fourthly, in increasing order of indexes for PUSCH slots.
5. The UE of claim 1 , wherein the SSBs are identified based on SSB configuration information included in the RACH configuration information and the SSB configuration information includes a SSB index, a random access preamble index and a PUSCH occasion index for a SSB.
6. A base station (BS), the BS comprising:
a transceiver; and
a processor configured to:
transmit, via the transceiver, random access channel (RACH) configuration information including CFRA-SSB-Resource information and msgA-PUSCH-Resource-CFRA information to a user equipment (UE), wherein the msgA-PUSCH-Resource-CFRA information includes at least one physical uplink shared channel (PUSCH) occasion, each PUSCH occasion is indexed, and wherein the CFRA-SSB-Resource information includes PUSCH occasion index information indicating an indexed PUSCH occasion, and
receive, via the transceiver, a message A based on a random access occasion and a PUSCH occasion identified based on the RACH configuration information,
wherein in case that a type of a random access is identified as 2-step contention free random access (CFRA) based on the RACH configuration information;
a synchronization signal block (SSB) with synchronization signal-reference signal received power (SS-RSRP) above a configured threshold among SSBs is selected at the UE,
the random access occasion corresponding to the selected SSB is identified at the UE, and
the PUSCH occasion from among the at least one PUSCH occasion configured in the msgA-PUSCH-Resource-CFRA information is identified at the UE, according to the PUSCH occasion index information corresponding to the selected SSB.
7. The BS of claim 6 , wherein the msgA-PUSCH-Resource-CFRA information includes parameters regarding:
a modulation coding scheme (MCS) for the message A transmission on the PUSCH occasion,
a number of slots containing the at least one PUSCH occasion,
a number of time domain PUSCH occasions in each RACH slot,
a time offset with respect to a start of each RACH slot,
a start symbol and length of the PUSCH occasion,
a guard period between the at least one PUSCH occasion in a unit of symbols,
a resource block (RB)-level guard band between the at least one PUSCH occasion in a frequency domain,
an offset of a lowest PUSCH occasion in the frequency domain,
a number of RBs per PUSCH occasion,
a number of PUSCH occasions in the frequency domain in one time instance, and
a demodulation reference signal (DMRS) configuration for the at least one PUSCH occasion.
8. The BS of claim 6 , wherein at least one PUSCH occasion index is sequentially indexed and is mapped to the at least one PUSCH occasion corresponding to a RACH slot of the identified random access occasion.
9. The BS of claim 8 , wherein the at least one PUSCH occasion corresponding to the RACH slot is indexed by ordering:
firstly, in increasing order of frequency resource indexes for frequency multiplexed PUSCH occasions,
secondly, in increasing order of DMRS resource indexes within the PUSCH occasion, where a DMRS resource index is determined first in an ascending order of a DMRS port index and then in an ascending order of a DMRS sequence index,
thirdly, in increasing order of time resource indexes for time multiplexed PUSCH occasions within a PUSCH slot, and
fourthly, in increasing order of indexes for PUSCH slots.
10. The BS of claim 6 , wherein the SSBs are identified based on SSB configuration information included in the RACH configuration information and the SSB configuration information includes a SSB index, a random access preamble index and a PUSCH occasion index for a SSB.
11. A method of performing communication by a user equipment (UE), the method comprising:
receiving random access channel (RACH) configuration information including CFRA-SSB-Resource information and msgA-PUSCH-Resource-CFRA information from a base station (BS), wherein the msgA-PUSCH-Resource-CFRA information includes at least one physical uplink shared channel (PUSCH) occasion, each PUSCH occasion is indexed, and wherein the CFRA-SSB-Resource information includes PUSCH occasion index information indicating an indexed PUSCH occasion;
in case that a type of a random access is identified as 2-step contention free random access (CFRA) based on the RACH configuration information, selecting a synchronization signal block (SSB) with synchronization signal-reference signal received power (SS-RSRP) above a configured threshold among SSBs;
identifying a random access occasion corresponding to the selected SSB;
identifying a PUSCH occasion from among the at least one PUSCH occasion configured in the msgA-PUSCH-Resource-CFRA information, according to the PUSCH occasion index information corresponding to the selected SSB; and
performing a message A transmission based on the identified random access occasion and the identified PUSCH occasion.
12. The method of claim 11 , wherein the msgA-PUSCH-Resource-CFRA information includes parameters regarding:
a modulation coding scheme (MCS) for the message A transmission,
a number of slots containing the at least one PUSCH occasion,
a number of time domain PUSCH occasions in each RACH slot,
a time offset with respect to a start of each RACH slot,
a start symbol and length of the PUSCH occasion,
a guard period between the at least one PUSCH occasion in a unit of symbols,
a resource block (RB)-level guard band between the at least one PUSCH occasion in a frequency domain,
an offset of a lowest PUSCH occasion in the frequency domain,
a number of RBs per PUSCH occasion,
a number of PUSCH occasions in the frequency domain in one time instance, and
a demodulation reference signal (DMRS) configuration for the at least one PUSCH occasion.
13. The method of claim 11 , wherein at least one PUSCH occasion index is sequentially indexed and is mapped to the at least one PUSCH occasion corresponding to a RACH slot of the identified random access occasion.
14. The method of claim 13 , wherein the at least one PUSCH occasion corresponding to the RACH slot is indexed by ordering:
firstly, in increasing order of frequency resource indexes for frequency multiplexed PUSCH occasions,
secondly, in increasing order of DMRS resource indexes within the PUSCH occasion, where a DMRS resource index is determined first in an ascending order of a DMRS port index and then in an ascending order of a DMRS sequence index,
thirdly, in increasing order of time resource indexes for time multiplexed PUSCH occasions within a PUSCH slot, and
fourthly, in increasing order of indexes for PUSCH slots.
15. The method of claim 11 , wherein the SSBs are identified based on SSB configuration information included in the RACH configuration information and the SSB configuration information includes a SSB index, a random access preamble index and a PUSCH occasion index for a SSB.
16. A method of performing communication by a base station (BS), the method comprising:
transmitting random access channel (RACH) configuration information including CFRA-SSB-Resource information and msgA-PUSCH-Resource-CFRA information to a user equipment (UE), wherein the msgA-PUSCH-Resource-CFRA information includes at least one physical uplink shared channel (PUSCH) occasion, each PUSCH occasion is indexed, and wherein the CFRA-SSB-Resource information includes PUSCH occasion index information indicating an indexed PUSCH occasion, and
receiving a message A based on a random access occasion and a PUSCH occasion identified based on the RACH configuration information,
wherein in case that a type of a random access is identified as 2-step contention free random access (CFRA) based on the RACH configuration information;
a synchronization signal block (SSB) with synchronization signal-reference signal received power (SS-RSRP) above a configured threshold among SSBs is selected at the UE,
the random access occasion corresponding to the selected SSB is identified at the UE, and
the PUSCH occasion from among the at least one PUSCH occasion configured in the msgA-PUSCH-Resource-CFRA information is identified at the UE, according to the PUSCH occasion index information corresponding to the selected SSB.
17. The method of claim 16 , wherein the msgA-PUSCH-Resource-CFRA information includes parameters regarding:
a modulation coding scheme (MCS) for the message A transmission on the PUSCH occasion,
a number of slots containing the at least one PUSCH occasion,
a number of time domain PUSCH occasions in each RACH slot,
a time offset with respect to a start of each RACH slot,
a start symbol and length of the PUSCH occasion,
a guard period between the at least one PUSCH occasion in a unit of symbols,
a resource block (RB)-level guard band between the at least one PUSCH occasion in a frequency domain,
an offset of a lowest PUSCH occasion in the frequency domain,
a number of RBs per PUSCH occasion,
a number of PUSCH occasions in the frequency domain in one time instance, and
a demodulation reference signal (DMRS) configuration for the at least one PUSCH occasion.
18. The method of claim 16 , wherein at least one PUSCH occasion index is sequentially indexed and is mapped to the at least one PUSCH occasion corresponding to a RACH slot of the identified random access occasion.
19. The method of claim 18 , wherein the at least one PUSCH occasion corresponding to the RACH slot is indexed by ordering:
firstly, in increasing order of frequency resource indexes for frequency multiplexed PUSCH occasions,
secondly, in increasing order of DMRS resource indexes within the PUSCH occasion, where a DMRS resource index is determined first in an ascending order of a DMRS port index and then in an ascending order of a DMRS sequence index,
thirdly, in increasing order of time resource indexes for time multiplexed PUSCH occasions within a PUSCH slot, and
fourthly, in increasing order of indexes for PUSCH slots.
20. The method of claim 16 , wherein the SSBs are identified based on SSB configuration information included in the RACH configuration information and the SSB configuration information includes a SSB index, a random access preamble index and a PUSCH occasion index for a SSB.