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, transmission by the UE; 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, 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 in the BWP being greater than the threshold of 90, the FDRA field is padded with ⌈ log 2 N ∗ N + 1 / 2 ⌉ − 12 most significant bits,MSBs, 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. receiving a random access response, RAR, based on a physical random access channel, PRACH, transmission by the UE; 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, 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 in the BWP being greater than the threshold of 90, the FDRA field is padded with ⌈ log 2 N ∗ N + 1 / 2 ⌉ − 12 most significant bits,MSBs, (i) based on a number of physical resource blocks, PRBs, 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 in the BWP being greater than the threshold of 90, the FDRA field is padded with ⌈ log 2 N ∗ N + 1 / 2 ⌉ − 12 most significant bits,MSBs, 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 (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.