Reiterated downlink grant design for multiple transmission time interval grant support in ECC
Enhanced robustness for downlink burst transmissions using reiterated grants. A user equipment (UE) may receive multiple transmissions during multiple (e.g., consecutive, etc.) transmission time intervals (TTIs) as part of a downlink burst from a base station, where at least some of the TTIs may include an iteration of a grant and a data transmission. The grants may contain some common control information for TTIs of the downlink burst, as well as an indicator of how may TTIs come before and after. The UE may identify preceding and subsequent TTIs in the downlink burst by decoding any of the grant iterations. If the UE identifies a previous transmission that has not been buffered, it may send a negative acknowledgement to the base station. If the previous transmission has been buffered, the UE may decode the previous transmission based at least in part on the current grant iteration.
1. A method of wireless communication comprising:
receiving a first grant and a first data transmission during a first transmission time interval of a plurality of transmission time intervals of a downlink burst, the first grant comprising control information for each transmission time interval of the plurality of transmission time intervals and indicating a count of a number of preceding transmission time intervals and a count of a number of subsequent transmission time intervals in the downlink burst;
identifying that the count of the number of preceding transmission time intervals is greater than zero and the count of the number of subsequent transmission time intervals is greater than zero in the downlink burst based at least in part on decoding the first grant;
receiving a second data transmission during a second transmission time interval of the plurality of transmission time intervals; and
decoding the first data transmission and the second data transmission based at least in part on the decoding the first grant.
2. The method of claim 1 , further comprising:
determining that a preceding one of the plurality of transmission time intervals has not been decoded based at least in part on the count of the number of preceding transmission time intervals; and
transmitting a negative acknowledgement (NACK) corresponding to the preceding transmission time interval.
3. The method of claim 1 , further comprising:
receiving a second grant during the second transmission time interval;
performing a cyclic redundancy check (CRC) on the second grant; and
determining that the second grant has not been decoded successfully based at least in part on the CRC.
4. The method of claim 3 , wherein decoding the first data transmission and the second data transmission based at least in part on decoding the first grant further comprises:
decoding data symbols of the second data transmission stored in a buffer based at least in part on the first grant.
5. The method of claim 1 , wherein the plurality of transmission time intervals are consecutive and each have a same transmission time interval length.
6. The method of claim 1 , further comprising:
receiving a second grant during the second transmission time interval, the second grant comprising the control information.
7. The method of claim 1 , further comprising:
determining that a grant was not received during the second transmission time interval.
8. The method of claim 1 , wherein each of the plurality of transmission time intervals comprises a plurality of subframes.
9. The method of claim 1 , wherein each of the plurality of transmission time intervals is associated with a same hybrid automatic repeat request (HARQ) process.
10. The method of claim 1 , wherein the control information comprises modulation and coding scheme information, rank information, a precoding matrix indicator, a resource location, or any combination thereof.
11. A method of wireless communication comprising:
identifying a plurality of transmission time intervals for a downlink burst;
transmitting a first grant and a first data transmission during a first transmission time interval of the plurality of transmission time intervals, the first grant comprising control information for each transmission time interval of the plurality of transmission time intervals and indicating a count of a number of preceding transmission time intervals and a count of a number of subsequent transmission time intervals in the downlink burst, wherein the count of the number of preceding transmission time intervals is greater than zero and the count of the number of subsequent transmission time intervals is greater than zero in the downlink burst; and
transmitting a second data transmission during a second transmission time interval of the plurality of transmission time intervals.
12. The method of claim 11 , wherein the plurality of transmission time intervals are consecutive and each have a same transmission time interval length.
13. The method of claim 11 , further comprising:
transmitting a second grant during the second transmission time interval, the second grant comprising the control information.
14. The method of claim 11 , further comprising:
determining not to transmit a grant during the second transmission time interval.
15. The method of claim 11 , wherein each of the plurality of transmission time intervals comprises a plurality of subframes, wherein the plurality of subframes have a first subframe duration that is shorter than a second subframe duration, and wherein the first subframe duration and the second subframe duration are supported by a same wireless network.
16. The method of claim 11 , wherein each data transmission of the plurality of transmission time intervals is associated with a same hybrid automatic repeat request (HARQ) process.
17. An apparatus for wireless communication, comprising:
a processor; and
memory, in communication with the processor, storing instructions that, when executed by the processor, cause the apparatus to:
receive a first grant and a first data transmission during a first transmission time interval of a plurality of transmission time intervals of a downlink burst, the first grant comprising control information for each transmission time interval of the plurality of transmission time intervals and indicating a count of a number of preceding transmission time intervals and a count of a number of subsequent transmission time intervals in the downlink burst;
identify that the count of the number of preceding transmission time intervals is greater than zero and the count of the number of subsequent transmission time intervals is greater than zero in the downlink burst based at least in part on decoding the first grant;
receive a second data transmission during a second transmission time interval of the plurality of transmission time intervals; and
decode the first data transmission and the second data transmission based at least in part on the decoding the first grant.
18. The apparatus of claim 17 , wherein the instructions are operable to cause the processor to:
determine that a preceding one of the plurality of transmission time intervals has not been decoded based at least in part on the count of the number of preceding transmission time intervals; and
transmit a negative acknowledgement (NACK) corresponding to the preceding transmission time interval.
19. The apparatus of claim 17 , wherein the instructions are operable to cause the processor to:
receive a second grant during the second transmission time interval of the downlink burst;
perform a cyclic redundancy check (CRC) on the second grant; and determine that the second grant has not been decoded successfully based at least in part on the CRC.
20. The apparatus of claim 19 , wherein decoding the first data transmission and the second data transmission based at least in part on decoding the first grant comprises:
decoding data symbols of the second data transmission stored in a buffer based at least in part on the first grant.
21. The apparatus of claim 17 , wherein the plurality of transmission time intervals are consecutive and each have a same transmission time interval length.
22. The apparatus of claim 17 , wherein the instructions are operable to cause the processor to receive a second grant during the second transmission time interval, the second grant comprising the control information.
23. The apparatus of claim 17 , wherein the instructions are operable to cause the processor to determine that a grant was not received during the second transmission time interval.
24. The apparatus of claim 17 , wherein each of the plurality of transmission time intervals is associated with a same hybrid automatic repeat request (HARQ) process.
25. An apparatus for wireless communication, comprising:
a processor; and
memory, in communication with the processor, storing instructions that, when executed by the processor, cause the apparatus to:
identify a plurality of transmission time intervals for a downlink burst;
transmit a first grant and a first data transmission during a first transmission time interval of the plurality of transmission time intervals, the first grant comprising control information for each transmission time interval of the plurality of transmission time intervals and indicating a count of a number of preceding transmission time intervals and a count of a number of subsequent transmission time intervals in the downlink burst, wherein the count of the number of preceding transmission time intervals is greater than zero and the count of the number of subsequent transmission time intervals is greater than zero in the downlink burst; and
transmit a second data transmission during a second transmission time interval of the plurality of transmission time intervals.
26. The apparatus of claim 25 , wherein the instructions are operable to cause the processor to determine not to transmit a grant during the second transmission time interval.