Base station and UE for communicating a RAR and PUSCH
A method and an apparatus for transmitting/receiving signals in a wireless communication system, according to one embodiment of the present invention, perform a 2- or 4-step random access process in a shared spectrum. In a method for interpreting an FDRA field for PUSCH transmissions corresponding to an RAR in a 4-step random access process or a fallback RAR in a 2-step random access process, the FDRA field is truncated to its X LSB, or the FDRA field is padded with Y MSB, on the basis of whether interlace allocation for a PUSCH for access to a shared spectrum channel is provided, and the FDRA field is interpreted as the FDRA field of downlink control information (DCI) format 0_0.
1. A method for transmitting and receiving signals by a user equipment (UE) operating in a wireless communication system, the method comprising:
receiving a random access response (RAR) based on a physical random access channel (PRACH); and
transmitting, in a bandwidth part (BWP), a physical uplink shared channel (PUSCH) for shared spectrum channel access, based on the RAR;
wherein a frequency domain resource allocation in the BWP for the PUSCH transmission is based on a frequency domain resource assignment (FDRA) field in the RAR,
wherein, based on information regarding interlace allocation of the PUSCH being not provided by higher-layer signaling:
(i) based on a number of physical resource blocks (PRBs) (N) in the BWP being equal to or less than a threshold of 90, the FDRA field is truncated to ┌log 2 (N*(N+1)/2)┐ least significant bits (LSBs), and
(ii) based on the number of PRBs (N) in the BWP being greater than the threshold of 90, ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 are inserted to the FDRA field,
wherein, based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling:
(i) based on a subcarrier spacing (SCS) for the BWP being 30 kHz, the FDRA field is truncated to 5 LSBs, or
(ii) based on the SCS for the BWP being 15 kHz, the FDRA field is truncated to 6 LSBs, and
wherein the FDRA field is interpreted as a FDRA field in downlink control information (DCI) format 0_0.
2. The method of claim 1 , wherein:
based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling, an uplink resource allocation type 1 is used, and
based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling, an uplink resource allocation type 2 is used.
3. The method of claim 1 , wherein:
for the shared spectrum channel access, the FDRA field of 12 bits is received from a base station.
4. The method of claim 3 , wherein the threshold of 90 is determined in consideration of a maximum number of PRBs in the BWP that can be indicated by 12 bits when resources are allocated based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling.
5. The method of claim 1 , wherein:
the ┌log 2 (N*(N+1)/2)┐−12 bits with a value set to 0 are inserted to the FDRA field after a number of bits related to an uplink frequency hopping,
based on a frequency hopping flag field in the RAR being set to 0, the number of bits related to the uplink frequency hopping is 0, and
based on the frequency hopping flag field in the RAR being set to 1, the number of bits related to the uplink frequency hopping is not 0.
6. 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 coupled to the at least one processor and storing instructions that, based on being executed, cause the at least one processor to perform operations comprising;
receiving a random access response (RAR) based on a physical random access channel (PRACH); and
transmitting, in a bandwidth part (BWP), a physical uplink shared channel (PUSCH) for shared spectrum channel access, based on the RAR,
wherein a frequency domain resource allocation in the BWP for the PUSCH transmission is based on a frequency domain resource assignment (FDRA) field in the RAR,
wherein, based on information regarding interlace allocation of the PUSCH being not provided by higher-layer signaling:
(i) based on a number of physical resource blocks (PRBs) (N) in the BWP being equal to or less than a threshold of 90, the FDRA field is truncated to ┌log 2 (N*(N+1)/2)┐ least significant bits (LSBs), and
(ii) based on the number of PRBs (N) in the BWP being greater than the threshold of 90, ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 are inserted to the FDRA field,
wherein, based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling:
(i) based on a subcarrier spacing (SCS) for the BWP being 30 kHz, the FDRA field is truncated to 5 LSBs, or
(ii) based on the SCS for the BWP being 15 kHz, the FDRA field is truncated to 6 LSBs, and
wherein the FDRA field is interpreted as a FDRA field in downlink control information (DCI) format 0_0.
7. The UE of claim 6 , wherein:
based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling, an uplink resource allocation type 1 is used, and
based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling, an uplink resource allocation type 2 is used.
8. The UE of claim 6 , wherein:
for the shared spectrum channel access, the FDRA field of 12 bits is received from a base station.
9. The UE of claim 8 , wherein:
the threshold of 90 is determined in consideration of a maximum number of PRBs in the BWP that can be indicated by 12 bits when resources are allocated based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling.
10. The method of claim 6 , wherein:
the ┌log 2 (N*(N+1)/2)┐−12 bits with a value set to 0 are inserted to the FDRA field after a number of bits related to an uplink frequency hopping,
based on a frequency hopping flag field in the RAR being set to 0, the number of bits related to the uplink frequency hopping is 0, and
based on the frequency hopping flag field in the RAR being set to 1, the number of bits related to the uplink frequency hopping is not 0.
11. A method for transmitting and receiving signals by a base station operating in a wireless communication system, the method comprising:
transmitting a random access response (RAR) based on a physical random access channel (PRACH); and
receiving, in a bandwidth part (BWP), a physical uplink shared channel (PUSCH) for shared spectrum channel access, based on the RAR;
wherein a frequency domain resource allocation in the BWP for the PUSCH transmission is based on a frequency domain resource assignment (FDRA) field in the RAR,
wherein, based on information regarding interlace allocation of the PUSCH being not provided by higher-layer signaling:
(i) based on a number of physical resource blocks (PRBs) (N) in the BWP being equal to or less than a threshold of 90, the FDRA field is truncated to ┌log 2 (N*(N+1)/2)┐ least significant bits (LSBs), and
(ii) based on the number of PRBs (N) in the BWP being greater than the threshold of 90, ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 are inserted to the FDRA field.
wherein, based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling:
(i) based on a subcarrier spacing (SCS) for the BWP being 30 kHz, the FDRA field is truncated to 5 LSBs, or
(ii) based on the SCS for the BWP being 15 kHz, the FDRA field is truncated to 6 LSBs, and
wherein the FDRA field is interpreted as a FDRA field in downlink control information (DCI) format 0_0.
12. The method of claim 11 , wherein:
based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling, an uplink resource allocation type 1 is used, and
based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling, an uplink resource allocation type 2 is used.
13. The method of claim 11 , wherein:
for the shared spectrum channel access, the FDRA field of 12 bits is transmitted by the base station.
14. The method of claim 13 , wherein:
the threshold of 90 is determined in consideration of a maximum number of PRBs in the BWP that can be indicated by 12 bits when resources are allocated based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling.
15. The method of claim 9 , wherein:
the ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 are inserted to the FDRA field after a number of bits related to an uplink frequency hopping,
based on a frequency hopping flag field in the RAR being set to 0, the number of bits related to the uplink frequency hopping is 0, and
based on the frequency hopping flag field in the RAR being set to 1, the number of bits related to the uplink frequency hopping is not 0.
16. A method for transmitting and receiving signals by a user equipment (UE) operating in a wireless communication system, the method comprising:
receiving a random access response (RAR) based on a physical random access channel (PRACH); and
transmitting, in a bandwidth part (BWP), a physical uplink shared channel (PUSCH) for shared spectrum channel access, based on the RAR;
wherein a frequency domain resource allocation in the BWP for the PUSCH transmission is based on a frequency domain resource assignment (FDRA) field in the RAR,
wherein, based on information regarding interlace allocation of the PUSCH being not provided by higher-layer signaling:
(i) based on a number of physical resource blocks (PRBs) (N) in the BWP being equal to or less than a threshold of 90, the FDRA field is truncated to ┌log 2 (N*(N+1)/2)┐−12 least significant bits (LSBs), and
(ii) based on the number of PRBs (N) in the BWP being greater than the threshold of 90, the FDRA field is expanded to include ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 that are inserted to the FDRA field,
wherein, based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling:
(i) based on a subcarrier spacing (SCS) for the BWP being 30kHz, the FDRA field is truncated to 5 LSBs, or
(ii) based on the SCS for the BWP being 15 kHz, the FDRA field is truncated to 6 LSBs, and
wherein the FDRA field is interpreted as a FDRA field in downlink control information (DCI) format 0_0.
17. The method of claim 16 , wherein:
based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling, an uplink resource allocation type 1 is used, and
based on the information regarding the interlace allocation of the PUSCH being provided by the higher-layer signaling, an uplink resource allocation type 2 is used.
18. The method of claim 16 , wherein:
for the shared spectrum channel access, the FDRA field of 12 bits is received from a base station.
19. The method of claim 18 , wherein the threshold of 90 is determined in consideration of a maximum number of PRBs in the BWP that can be indicated by 12 bits when resources are allocated based on the information regarding the interlace allocation of the PUSCH being not provided by the higher-layer signaling.
20. The method of claim 16 , wherein:
the ┌log 2 (N*(N+1)/2)┐−12 bits with value set to 0 are inserted to the FDRA field after a number of bits related to an uplink frequency hopping,
based on a frequency hopping flag field in the RAR being set to 0, the number of bits related to the uplink frequency hopping is 0, and
based on the frequency hopping flag field in the RAR being set to 1, the number of bits related to the uplink frequency hopping is not 0.