TTI-bundling and SPS operation in LTE TDD

1. A method of wireless communication, comprising:

receiving a semi-persistent scheduling (SPS) message indicating transmission of a first packet during a first period of a first hybrid automatic repeat request (HARQ) process;

receiving an uplink/downlink configuration for transmission time interval-bundled (TTI-bundled) transmission;

transmitting a first TTI-bundled packet on first resources during the first period of the first HARQ process;

identifying second resources for transmitting a second TTI-bundled packet during a second period of the first HARQ process based on the SPS message; and

determining to offset transmission of the second TTI-bundled packet to a period of a second HARQ process when at least one of the second resources for transmitting the second TTI-bundled packet overlaps with at least one resource used for retransmitting the first TTI-bundled packet according to the first HARQ process.

2. The method of claim 1 , wherein the determining is based on at least one of the uplink/downlink configuration or a number of available HARQ processes among the plurality of HARQ processes.

3. The method of claim 1 , wherein the transmission of the second TTI-bundled packet is not offset to the period of the second HARQ process when the transmitted first TTI-bundled packet is successfully received during the first period of the first HARQ process.

4. The method of claim 1 , wherein one or more values of the offset are determined based on a radio resource control (RRC) configuration for predetermined SPS instances received from a base station.

5. The method of claim 4 , wherein the one or more values of the offset are repeated cyclically based on the RRC configuration for the predetermined SPS instances.

6. The method of claim 1 , wherein one or more values of the offset are determined based on a list of predefined offsets.

7. The method of claim 6 , wherein the one or more values of the offset are repeated cyclically based on the list of predefined offsets.

8. The method of claim 1 , wherein one or more values of the offset are determined based on an indication provided in scheduling information received from a base station.

9. The method of claim 1 , wherein the determining whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process comprises:

determining a next available HARQ process for transmitting the second TTI-bundled packet and a corresponding offset value for the next available HARQ process if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and the retransmission of the first packet is expected.

10. The method of claim 9 , wherein the determining whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process further comprises:

dropping the retransmission of the first TTI-bundled packet if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and there is no other available HARQ process for transmitting the second TTI-bundled packet.

11. An apparatus for wireless communication, comprising:

means for receiving a semi-persistent scheduling (SPS) message indicating transmission of a first packet during a first period of a first hybrid automatic repeat request (HARQ) process;

means for receiving an uplink/downlink configuration for transmission time interval-bundled (TTI-bundled) transmission;

means for transmitting a first TTI-bundled packet on first resources during the first period of the first HARQ process;

means for identifying second resources for transmitting a second TTI-bundled packet during a second period of the first HARQ process based on the SPS message; and

means for determining to offset transmission of the second TTI-bundled packet to a period of a second HARQ process when at least one of the second resources for transmitting the second TTI-bundled packet overlaps with at least one resource used for retransmitting the first TTI-bundled packet according to the first HARQ process.

12. The apparatus of claim 11 , wherein the means for determining determines based on at least one of the uplink/downlink configuration or a number of available HARQ processes among the plurality of HARQ processes.

13. The apparatus of claim 11 , wherein the transmission of the second TTI-bundled packet is not offset to the period of the second HARQ process when the transmitted first TTI-bundled packet is successfully received during the first period of the first HARQ process.

14. The apparatus of claim 11 , wherein one or more values of the offset are determined based on a radio resource control (RRC) configuration for predetermined SPS instances received from a base station.

15. The apparatus of claim 14 , wherein the one or more values of the offset are repeated cyclically based on the RRC configuration for the predetermined SPS instances.

16. The apparatus of claim 11 , wherein one or more values of the offset are determined based on a list of predefined offsets.

17. The apparatus of claim 16 , wherein the one or more values of the offset are repeated cyclically based on the list of predefined offsets.

18. The apparatus of claim 11 , wherein one or more values of the offset are determined based on an indication provided in scheduling information received from a base station.

19. The apparatus of claim 11 , wherein the means for determining whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process is configured to:

determine a next available HARQ process for transmitting the second TTI-bundled packet and a corresponding offset value for the next available HARQ process if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and the retransmission of the first packet is expected.

20. The apparatus of claim 19 , wherein the means for determining whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process is further configured to:

drop the retransmission of the first TTI-bundled packet if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and there is no other available HARQ process for transmitting the second TTI-bundled packet.

21. An apparatus for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive a semi-persistent scheduling (SPS) message indicating transmission of a first packet during a first period of a first hybrid automatic repeat request (HARQ) process;

receive an uplink/downlink configuration for transmission time interval-bundled (TTI-bundled) transmission;

transmit a first TTI-bundled packet on first resources during the first period of the first HARQ process;

identify second resources for transmitting a second TTI-bundled packet during a second period of the first HARQ process based on the SPS message; and

determine to offset transmission of the second TTI-bundled packet to a period of a second HARQ process when at least one of the second resources for transmitting the second TTI-bundled packet overlaps with at least one resource used for retransmitting the first TTI-bundled packet according to the first HARQ process.

22. The apparatus of claim 21 , wherein the at least one processor configured to determine determines based on at least one of the uplink/downlink configuration or a number of available HARQ processes among the plurality of HARQ processes.

23. The apparatus of claim 21 , wherein the transmission of the second TTI-bundled packet is not offset to the period of the second HARQ process when the transmitted first TTI-bundled packet is successfully received during the first period of the first HARQ process.

24. The apparatus of claim 21 , wherein one or more values of the offset are determined based on a radio resource control (RRC) configuration for predetermined SPS instances received from a base station.

25. The apparatus of claim 24 , wherein the one or more values of the offset are repeated cyclically based on the RRC configuration for the predetermined SPS instances.

26. The apparatus of claim 21 , wherein one or more values of the offset are determined based on a list of predefined offsets.

27. The apparatus of claim 21 , wherein one or more values of the offset are determined based on an indication provided in scheduling information received from a base station.

28. The apparatus of claim 21 , wherein the at least one processor configured to determine whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process is configured to:

determine a next available HARQ process for transmitting the second TTI-bundled packet and a corresponding offset value for the next available HARQ process if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and the retransmission of the first packet is expected.

29. The apparatus of claim 28 , wherein the at least one processor configured to determine whether to offset the transmission of the second TTI-bundled packet to the period of the second HARQ process is further configured to:

drop the retransmission of the first TTI-bundled packet if the at least one of the second resources for transmitting the second TTI-bundled packet overlaps with the at least one resource used for retransmitting the first TTI-bundled packet and there is no other available HARQ process for transmitting the second TTI-bundled packet.

30. A computer program product stored on a non-transitory computer-readable medium and comprising code that when executed on at least one processor causes the at least one processor to:

receive a semi-persistent scheduling (SPS) message indicating transmission of a first packet during a first period of a first hybrid automatic repeat request (HARQ) process;

receive an uplink/downlink configuration for transmission time interval-bundled (TTI-bundled) transmission;

transmit a first TTI-bundled packet on first resources during the first period of the first HARQ process;

identify second resources for transmitting a second TTI-bundled packet during a second period of the first HARQ process based on the SPS message; and

determine to offset transmission of the second TTI-bundled packet to a period of a second HARQ process when at least one of the second resources for transmitting the second TTI-bundled packet overlaps with at least one resource used for retransmitting the first TTI-bundled packet according to the first HARQ process.