Construction and mapping of compact uplink control information (UCI) over physical uplink shared channel (PUSCH)

1. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors coupled with the memory, the one or more processors configured to:

receive downlink control information (DCI) that includes an indication of a physical uplink shared channel (PUSCH) resource unit (PRU) for a PUSCH communication;

transmit the PUSCH communication in the PRU, wherein the PUSCH communication includes a payload of a msgA communication in a contention-free two-step random access channel (RACH) procedure and uplink control information (UCI) multiplexed in the PUSCH communication, the UCI identifies one or more parameters associated with the PUSCH communication; and

determine that a combination of the PRU and a preamble of the msgA communication is associated with a plurality of different combinations of the one or more parameters, wherein the PUSCH communication includes the UCI based at least in part on the combination of the PRU and the preamble of the msgA communication being associated with the plurality of different combinations of the one or more parameters.

2. The UE of claim 1 , wherein the one or more parameters comprise at least one of:

a modulation coding scheme index associated with the PUSCH communication,

a redundancy version associated with the PUSCH communication, or

a transport block size associated with the PUSCH communication.

3. The UE of claim 1 , wherein the one or more processors are further configured to:

determine that a plurality of PRUs, included in a PRU group in which the PRU is included, are mapped to a shared set of time-domain resources and frequency-domain resources, wherein the PUSCH communication includes the UCI based at least in part on the plurality of PRUs being mapped to the shared set of time-domain resources and frequency-domain resources.

4. The UE of claim 3 , wherein the plurality of PRUs have a same time-domain resource size and a same frequency-domain resource size.

5. The UE of claim 3 , wherein at least a subset of the plurality of PRUs have at least one of different time-domain resource sizes or different frequency-domain resource sizes.

6. The UE of claim 1 , wherein the one or more processors are further configured to:

determine that a plurality of PRUs, included in a PRU group in which the PRU is included, are nested in a time domain and a frequency domain such that the plurality of PRUs share a same starting time-domain resource and a same starting frequency-domain resource, wherein the PUSCH communication includes the UCI based at least in part on the plurality of PRUs being nested in the time domain and the frequency domain such that the plurality of PRUs share the same starting time-domain resource and the same starting frequency-domain resource.

7. The UE of claim 1 , wherein the one or more parameters are indicated by a plurality of bits, and wherein the one or more processors are further configured to:

attach one or more cyclic redundancy check (CRC) bits to the plurality of bits to form a group of bits; and

channel code the group of bits to form coded bits.

8. The UE of claim 7 , wherein the one or more processors are further configured to:

determine that a quantity of bits, of the plurality of bits, fails to satisfy a bit quantity threshold; and

reduce the quantity of bits to a reduced quantity of bits based at least in part on the quantity of bits failing to satisfy the bit quantity threshold.

9. The UE of claim 8 , wherein the one or more processors are further configured to:

mask the one or more CRC bits based at least in part on a pseudo-random sequence that is based at least in part on the reduced quantity of bits.

10. The UE of claim 8 , wherein the one or more processors are further configured to:

scramble the coded bits using a pseudo-random sequence that is based at least in part on the reduced quantity of bits.

11. The UE of claim 1 , wherein one or more modulation symbols of the UCI are transmitted in one or more orthogonal frequency division multiplexing (OFDM) symbols adjacent to a transmission of a demodulation reference signal in the PRU and in one or more subcarriers that start at a semi-persistent subcarrier index of the PRU.

12. The UE of claim 11 , wherein modulation symbols of the PUSCH communication are punctured or rate matched in the PRU around the one or more subcarriers.

13. The UE of claim 11 , wherein a quantity of the one or more subcarriers is a same quantity of subcarriers for each PRU included in a PRU group in which the PRU is included.

14. A method of wireless communication performed by a user equipment (UE), comprising:

receiving downlink control information (DCI) that includes an indication of a physical uplink shared channel (PUSCH) resource unit (PRU) for a PUSCH communication;

transmitting the PUSCH communication in the PRU, wherein the PUSCH communication includes a payload of a msgA communication in a contention-free two-step random access channel (RACH) procedure and uplink control information (UCI) multiplexed in the PUSCH communication, the UCI identifies one or more parameters associated with the PUSCH communication; and

determining that a combination of the PRU and a preamble of the msgA communication is associated with a plurality of different combinations of the one or more parameters, wherein the PUSCH communication includes the UCI based at least in part on the combination of the PRU and the preamble of the msgA communication being associated with the plurality of different combinations of the one or more parameters.

15. The method of claim 14 , wherein the one or more parameters comprise at least one of:

a modulation coding scheme index associated with the PUSCH communication,

a redundancy version associated with the PUSCH communication, or

a transport block size associated with the PUSCH communication.

16. The method of claim 14 , further comprising:

determining that a plurality of PRUs, included in a PRU group in which the PRU is included, are mapped to a shared set of time-domain resources and frequency-domain resources, wherein the PUSCH communication includes the UCI based at least in part on the plurality of PRUs being mapped to the shared set of time-domain resources and frequency-domain resources.

17. The method of claim 16 , wherein the plurality of PRUs comprise a same time-domain resource size and a same frequency-domain resource size.

18. The method of claim 16 , wherein at least a subset of the plurality of PRUs are of at least one of different time-domain resource sizes or different frequency-domain resource sizes.

19. The method of claim 14 , further comprising:

determining that a plurality of PRUs, included in a PRU group in which the PRU is included, are nested in a time domain and a frequency domain such that the plurality of PRUs share a same starting time-domain resource and a same starting frequency-domain resource, wherein the PUSCH communication includes the UCI based at least in part on the plurality of PRUs being nested in the time domain and the frequency domain such that the plurality of PRUs share the same starting time-domain resource and the same starting frequency-domain resource.

20. The method of claim 14 , wherein the one or more parameters are indicated by a plurality of bits, wherein the method further comprises:

attaching one or more cyclic redundancy check (CRC) bits to the plurality of bits to form a group of bits; and

channel coding the group of bits to form coded bits.

21. The method of claim 20 , further:

determining that a quantity of bits, of the plurality of bits, fails to satisfy a bit quantity threshold; and

reducing the quantity of bits to a reduced quantity of bits based at least in part on the quantity of bits failing to satisfy the bit quantity threshold.

22. The method of claim 21 , further comprising:

masking the one or more CRC bits based at least in part on a pseudo-random sequence that is based at least in part on the reduced quantity of bits.

23. The method of claim 21 , further comprising:

scrambling the coded bits using a pseudo-random sequence that is based at least in part on the reduced quantity of bits.

24. The method of claim 14 , wherein one or more modulation symbols of the UCI are transmitted in one or more orthogonal frequency division multiplexing (OFDM) symbols adjacent to a transmission of a demodulation reference signal in the PRU and in one or more subcarriers that start at a semi-persistent subcarrier index of the PRU.

25. The method of claim 24 , wherein modulation symbols of the PUSCH communication are punctured or rate matched in the PRU around the one or more subcarriers.

26. The method of claim 24 , wherein a quantity of the one or more subcarriers is a same quantity of subcarriers for each PRU included in a PRU group in which the PRU is included.

27. A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE), cause the UE to:

receive downlink control information (DCI) that includes an indication of a physical uplink shared channel (PUSCH) resource unit (PRU) for a PUSCH communication;

transmit the PUSCH communication in the PRU, wherein the PUSCH communication includes a payload of a msgA communication in a contention-free two-step random access channel (RACH) procedure and uplink control information (UCI) multiplexed in the PUSCH communication, the UCI identifies one or more parameters associated with the PUSCH communication; and

determine that a combination of the PRU and a preamble of the msgA communication is associated with a plurality of different combinations of the one or more parameters, wherein the PUSCH communication includes the UCI based at least in part on the combination of the PRU and the preamble of the msgA communication being associated with the plurality of different combinations of the one or more parameters.

28. An apparatus for wireless communication, comprising:

means for receiving downlink control information (DCI) that includes an indication of a physical uplink shared channel (PUSCH) resource unit (PRU) for a PUSCH communication;

means for transmitting the PUSCH communication in the PRU, wherein the PUSCH communication includes a payload of a msgA communication in a contention-free two-step random access channel (RACH) procedure and uplink control information (UCI) multiplexed in the PUSCH communication, the UCI identifies one or more parameters associated with the PUSCH communication; and

means for determining that a combination of the PRU and a preamble of the msgA communication is associated with a plurality of different combinations of the one or more parameters, wherein the PUSCH communication includes the UCI based at least in part on the combination of the PRU and the preamble of the msgA communication being associated with the plurality of different combinations of the one or more parameters.