Dynamic code block group (CBG) allocation
Certain aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for xx. A method that may be performed by a user equipment (UE) includes receiving, from a network entity, a first transport block (TB) comprising one or more code blocks (CBs), transmitting, to the network entity, an indication of a preferred code block group (CBG) allocation scheme selected for re-transmission of at least one CB of the one or more CBs based, at least in part, on a decoding status for each of the one or more CBs, and receiving, from the network entity, the at least one CB re-transmitted in accordance with the preferred CBG allocation scheme.
1. A method for wireless communication by a user equipment (UE), the method comprising:
receiving, from a network entity, a first transport block (TB) comprising one or more code blocks (CBs);
transmitting, to the network entity, an indication of a time domain-based code block group (CBG) allocation scheme or a frequency domain-based CBG allocation scheme selected based, at least in part, on a decoding status for the one or more CBs; and
receiving, from the network entity, one or more subsequent transmissions in accordance with the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme.
2. The method of claim 1 , further comprising transmitting, to the network entity, uplink control information (UCI) carrying at least one of acknowledgement (ACK) feedback or negative ACK (NACK) feedback for each of one or more CBGs containing the one or more CBs of the first TB, wherein the ACK feedback and the NACK feedback is based on the decoding status for each of the one or more CBs of the first TB.
3. The method of claim 2 , wherein the indication of the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme comprises a bit added to a bit structure of the UCI.
4. The method of claim 1 , further comprising receiving, from the network entity, in response to transmitting the indication of the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme, downlink control information (DCI) indicating the time domain-based CBG allocation scheme or the frequency domain-based CBG allocation scheme.
5. The method of claim 4 , wherein the indication of the time domain-based CBG allocation scheme or the frequency domain-based CBG allocation scheme comprises a bit added to a bit structure of the DCI.
6. The method of claim 1 , wherein:
the time domain-based CBG allocation scheme maps CBs into CBGs in a frequency-first, time-second manner;
determining, based on the time domain-based CBG allocation scheme, a first number of first CBGs containing CBs of the first TB with the decoding status indicating a failure to decode by the UE;
the frequency domain-based CBG allocation scheme maps CBs into CBGs in a time-first, frequency-second manner; and
determining, based on the frequency domain-based CBG allocation, a second number of CBGs containing the CBs of the first TB with the decoding status indicating a failure to decode by the UE.
7. The method of claim 6 , wherein:
when the first number of CBGs is greater than the second number of CBGs, selecting to indicate the frequency domain-based CBG allocation scheme;
when the first number of CBGs is less than the second number of second CBGs, selecting to indicate the time domain-based CBG allocation scheme; and
when the first number of CBGs is equal to the second number of CBGs, selecting to indicate a default one of the time domain-based CBG allocation scheme and the frequency domain-based CBG allocation scheme or selecting a time domain-based CBG allocation scheme or a frequency domain-based CBG allocation scheme used for re-transmission of CBs of a previously received TB.
8. The method of claim 1 , further comprising determining the frequency domain-based CBG allocation scheme, wherein determining the frequency domain-based CBG allocation scheme comprises:
estimating a number of CBGs containing one or more CBs of a TB comprising a total number of CBs; and
estimating a number of the one or more CBs contained in each of the number of the CBGs.
9. The method of claim 8 , further comprising:
estimating a number of symbols used to transmit the TB;
dividing the total number of CBs of the TB among the estimated number of symbols, wherein a number of the CBs, of the total number of CBs, allocated to each symbol of the number of symbols is equal or differs by one;
determining a number of CBGs; and
dividing the the number of CBs allocated to each respective symbol, of the number of symbols, among the determined number of CBGs, wherein a number of CBs, of the total number of CBs, allocated to each CBG of the number of CBGs is equal or differs by one.
10. The method of claim 9 , wherein the estimating the number of the symbols used to transmit the TB comprises ignoring symbols used to transmit other downlink transmissions, the other downlink transmissions including at least one of; a physical downlink control channel (PDCCH) or a demodulation reference signal (DMRS).
11. The method of claim 9 , wherein the dividing the total number of CBs among the estimated number of symbols comprising dividing the total number of CBs among the estimated number of symbols in frequency resources spanning an entire frequency band.
12. A method for wireless communication by a network entity, the method comprising:
transmitting, to a user equipment (UE), a first transport block (TB) comprising one or more code blocks (CBs);
receiving, from the UE, an indication of a selected time domain-based code block group (CBG) allocation scheme or a frequency domain-based CBG allocation scheme; and
transmitting, to the UE, a subsequent transmission in accordance with the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme.
13. The method of claim 12 , further comprising receiving, from the UE, uplink control information (UCI) carrying at least one of acknowledgement (ACK) feedback or negative ACK (NACK) feedback for each of one or more CBGs containing the one or more CBs of the first TB.
14. The method of claim 13 , wherein the indication of the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme comprises a bit added to a bit structure of the UCI.
15. The method of claim 12 , further comprising transmitting, to the UE, in response to receiving the indication of the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme, downlink control information (DCI) indicating the time domain-based CBG allocation scheme or the frequency domain-based CBG allocation scheme, wherein the CBG allocation scheme is selected by the network entity based, at least in part, on the indication of the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme.
16. The method of claim 15 , wherein the indication of the time domain-based CBG allocation scheme or the frequency domain-based CBG allocation scheme comprises a bit added to a bit structure of the DCII.
17. The method of claim 12 , wherein:
the time domain-based CBG allocation scheme maps CBs into CBGs in a frequency-first, time-second manner; or
the frequency domain-based CBG allocation scheme maps CBs into CBGs in a time-first, frequency-second manner.
18. The method of claim 17 , further comprising determining the frequency domain-based CBG allocation scheme, wherein determining the frequency domain-based CBG allocation scheme comprises:
estimating a number of CBGs containing CBs of a TB comprising a total number of CBs; and
estimating a number of CBs, of the total number of CBs, contained in each of the estimated number of CBGs.
19. The method of claim 18 , further comprising:
estimating a number of symbols used to transmit the TB;
dividing the total number of CBs of the TB among the estimated number of symbols, wherein a number of the CBs, of the total number of CBs, allocated to each symbol of the number of symbols is equal or differs by one;
determining a number of CBGs; and
dividing the number of CBs allocated to each respective symbol, of the number of symbols, among the determined number of CBGs, wherein a number of CBs, of the total number of CBs, allocated to each CBG of the number of CBGs is equal or differs by one.
20. The method of claim 19 , wherein the estimating the number of the symbols used to transmit the TB comprises ignoring symbols used to transmit other downlink transmissions, the other downlink transmissions including at least one of; a physical downlink control channel (PDCCH) or a demodulation reference signal (DMRS).
21. The method of claim 19 , wherein the dividing the total number of CBs among the estimated number of symbols comprising dividing the total number of CBs among the estimated number of symbols in frequency resources spanning an entire frequency band.
22. An apparatus for wireless communication by a user equipment (UE), the apparatus comprising:
at least one processor; and
a memory coupled to the at least one processor, the memory including instructions executable by the at least one processor to cause the apparatus to:
receive, from a network entity, a first transport block (TB) comprising one or more code blocks (CBs);
transmit, to the network entity, an indication of a time domain-based code block group (CBG) allocation scheme or a frequency domain-based CBG allocation scheme selected for re-transmission of at least one CB of the one or more CBs based, at least in part, on a decoding status for the one or more CBs; and
receive, from the network entity, one or more subsequent transmissions in accordance with the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme.
23. The apparatus of claim 22 , wherein the memory further includes instructions executable by the at least one processor to cause the apparatus to transmit, to the network entity, uplink control information (UCI) carrying at least one of acknowledgement (ACK) feedback or negative ACK (NACK) feedback for each of one or more CBGs containing the one or more CBs of the first TB, and wherein the ACK feedback and the NACK feedback is based on the decoding status for each of the one or more CBs of the first TB.
24. The apparatus of claim 22 , wherein the memory further includes instructions executable by the at least one processor to cause the apparatus to:
the time domain-based CBG allocation scheme maps CBs into CBGs in a frequency-first, time-second manner;
determine, based on the time domain-based CBG allocation scheme, a first number of first CBGs containing CBs of the first TB with the decoding status indicating a failure to decode by the UE;
the frequency domain-based CBG allocation scheme maps CBs into CBGs in a time-first, frequency-second manner; and
determine, based on the frequency domain-based CBG allocation, a second number of second CBGs containing the CBs of the first TB with the decoding status indicating a failure to decode by the UE; and
determine whether the number of first CBGs is greater than the number of second CBGs, less than the number of second CBGs, or equal to the number of second CBGs.
25. The apparatus of claim 24 , wherein the memory further includes instructions executable by the at least one processor to cause the apparatus to:
when the first number of first CBGs is greater than the second number of second CBGs, select to indicate the preferred CBG allocation scheme comprises the frequency domain-based CBG allocation scheme;
when the first number of first CBGs is less than the second number of second CBGs, select to indicate the preferred CBG allocation scheme comprises the time domain-based CBG allocation scheme; and
when the first number of first CBGs is equal to the second number of second CBGs, select to indicate the preferred CBG allocation scheme comprises at least one of a default one of the time domain-based CBG allocation scheme and the frequency domain-based CBG allocation scheme or selecting a time domain-based CBG allocation scheme or a frequency domain-based CBG allocation scheme used for re-transmission of CBs of a previously received TB.
26. An apparatus for wireless communication by a network entity, comprising:
at least one processor; and
a memory coupled to the at least one processor, the memory including instructions executable by the at least one processor to cause the apparatus to:
transmit, to a user equipment (UE), a first transport block (TB) comprising one or more code blocks (CBs);
receive, from the UE, an indication of a selected time domain-based code block group (CBG) allocation scheme or a frequency domain-based CBG allocation scheme; and
transmit, to the UE, a subsequent transmission in accordance with the selected time domain-based CBG allocation scheme or frequency domain-based CBG allocation scheme.