Conditional HARQ feedback

1. A method for wireless communication at a receiving device, comprising:

receiving a data transmission for communications having a latency requirement less than a threshold;

determining a reduced transmission time interval (TTI) for feedback signaling based at least in part on the received data transmission;

evaluating a condition for determining information to include as hybrid automatic repeat request (HARQ) feedback in response to the data transmission, wherein evaluating the condition includes receiving a modulation and coding scheme (MCS) index, and determining that the MCS index is below an MCS index threshold; and

modifying a HARQ feedback operation based at least in part on determining the reduced TTI and determining that the MCS index is below the MCS index threshold.

2. The method of claim 1 , further comprising:

receiving a device configuration indicating that HARQ feedback is to be turned off, wherein the device configuration is the condition to be evaluated.

3. The method of claim 1 , further comprising:

receiving an indication in a control channel that HARQ feedback for the data transmission is to be turned off, wherein the indication is the condition to be evaluated.

4. The method of claim 1 , wherein evaluating the condition for determining information to include as HARQ feedback comprises:

determining that the receiving device is power-limited and that, based at least in part on the determining, HARQ feedback is to be turned off.

5. The method of claim 1 , wherein modifying the HARQ feedback operation based at least in part on the condition comprises:

modifying the HARQ feedback operation to exclude negative acknowledgement (NAK) reporting.

6. The method of claim 5 , wherein modifying the HARQ feedback operation to exclude NAK reporting comprises one or both of excluding NAK reporting based at least in part on an indication received in a control channel or excluding NAK reporting based at least in part on a determination that a received power of a reference signal at the receiving device is below a predetermined threshold.

7. The method of claim 1 , wherein modifying the HARQ feedback operation based at least in part on the condition comprises:

modifying the HARQ feedback operation to exclude acknowledgment (ACK) reporting.

8. The method of claim 7 , wherein modifying the HARQ feedback operation to exclude ACK reporting comprises one or both of excluding ACK reporting based at least in part on an indication received in a control channel, excluding ACK reporting based at least in part on a determination that the receiving device is power-limited, or excluding ACK reporting based at least in part on a determination that a received power of a reference signal at the receiving device is above a predetermined threshold.

9. The method of claim 1 , wherein evaluating the condition for determining information to include as HARQ feedback comprises:

determining channel or traffic conditions.

10. The method of claim 1 , wherein modifying the HARQ feedback operation based at least in part on the condition comprises:

using a transmission time interval (TTI) for HARQ feedback that is longer than a TTI used for the data transmission.

11. The method of claim 1 , further comprising:

transmitting to a sending device that sent the data transmission an indication that the HARQ feedback operation has been modified.

12. The method of claim 11 , wherein transmitting the indication comprises:

transmitting the indication periodically or in response to an aperiodic request.

13. The method of claim 11 , wherein transmitting the indication comprises:

including the indication as part of a physical layer payload or as part of a media access control (MAC) layer payload.

14. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to:

receive a data transmission for communications having a latency requirement less than a threshold;

determine a reduced transmission time interval (TTI) for feedback signaling based at least in part on the received data transmission;

evaluate a condition for determining information to include as hybrid automatic repeat request (HARQ) feedback in response to the data transmission, wherein evaluating the condition includes receiving a modulation and coding scheme (MCS) index, and determining that the MCS index is below an MCS index threshold; and

modify a HARQ feedback operation based at least in part on determining the reduced TTI and determining that the MCS index is below the MCS index threshold.

15. The method of claim 1 , wherein modifying the HARQ feedback operation comprises:

selecting one or more channel quality indicator (CQI) indices from a set of CQI indices, wherein the selected CQI indices correspond to an adjusted block error rate (BLER) based at least in part on the modified HARQ feedback operation; and

reporting the selected one or more CQI indices to a sending device.

16. The apparatus of claim 14 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive a device configuration indicating that HARQ feedback is to be turned off, wherein the device configuration is the condition to be evaluated.

17. The apparatus of claim 14 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive an indication in a control channel that HARQ feedback for the data transmission is to be turned off, wherein the indication is the condition to be evaluated.

18. The apparatus of claim 14 , wherein the instructions for evaluating the condition for determining information to include as HARQ feedback are further executable by the processor to cause the apparatus to:

determine that the receiving device is power-limited and that, based at least in part on the determining, HARQ feedback is to be turned off.

19. The apparatus of claim 14 , wherein the instructions for modifying the HARQ feedback operation based at least in part on the condition are further executable by the processor to cause the apparatus to:

modify the HARQ feedback operation to exclude negative acknowledgement (NAK) reporting.

20. The apparatus of claim 19 , wherein modifying the HARQ feedback operation to exclude NAK reporting comprises one or both of excluding NAK reporting based at least in part on an indication received in a control channel or excluding NAK reporting based at least in part on a determination that a received power of a reference signal at the receiving device is below a predetermined threshold.

21. The apparatus of claim 14 , wherein the instructions for modifying the HARQ feedback operation based at least in part on the condition are further executable by the processor to cause the apparatus to:

modify the HARQ feedback operation to exclude acknowledgment (ACK) reporting.

22. The apparatus of claim 21 , wherein modifying the HARQ feedback operation to exclude ACK reporting comprises one or both of excluding ACK reporting based at least in part on an indication received in a control channel, excluding ACK reporting based at least in part on a determination that the receiving device is power-limited, or excluding ACK reporting based at least in part on a determination that a received power of a reference signal at the receiving device is above a predetermined threshold.

23. The apparatus of claim 14 , wherein the instructions for evaluating the condition for determining information to include as HARQ feedback are further executable by the processor to cause the apparatus to:

determine channel or traffic conditions.

24. The apparatus of claim 14 , wherein the instructions for modifying the HARQ feedback operation based at least in part on the condition are further executable by the processor to cause the apparatus to:

using a transmission time interval (TTI) for HARQ feedback that is longer than a TTI used for the data transmission.

25. The apparatus of claim 14 , wherein the instructions are further executable by the processor to cause the apparatus to:

transmit to a sending device that sent the data transmission an indication that the HARQ feedback operation has been modified.

26. The apparatus of claim 25 , wherein the instructions for transmitting the indication are further executable by the processor to cause the apparatus to:

transmit the indication periodically or in response to an aperiodic.

27. The apparatus of claim 25 , wherein the instructions for transmitting the indication are further executable by the processor to cause the apparatus to:

include the indication as part of a physical layer payload or as part of a media access control (MAC) layer payload.

28. The apparatus of claim 14 , wherein the instructions for modifying the HARQ feedback are further executable by the processor to cause the apparatus to:

select one or more channel quality indicator (CQI) indices from a set of CQI indices, wherein the selected CQI indices correspond to an adjusted block error rate (BLER) based at least in part on the modified HARQ feedback operation; and

report the selected one or more CQI indices to a sending device.