Narrowband time-division duplex frame structure for narrowband communications

1. A method of wireless communications for a base station, comprising:

determining a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determining a first set of subframes in the TDD frame structure used for transmitting a downlink control channel to a user equipment (UE), a last subframe in the first set of subframes being subframe n;

determining a second set of subframes in the TDD frame structure used for transmitting a downlink data channel to the UE, a first subframe in the second set of subframes being delayed based on k 0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k 0 +x, x being an integer number;

signaling first information associated with the k 0 number or subframes to the UE in a first delay field, and second information associated with m 0 number of subframes to the UE in a second delay field in a downlink control information (DCI) transmission; and

determining an uplink subframe in the TDD frame structure used by the UE for reporting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel, the uplink subframe being delayed the m 0 number of subframes after the subframe n+k 0 +x, the m 0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

2. The method of claim 1 , further comprising:

receiving a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

3. The method of claim 1 , wherein:

the first information indicates a k 0 number of valid downlink subframes, and

the second information indicates a m 0 number of valid uplink subframes.

4. An apparatus for wireless communications for a base station, comprising:

means for determining a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

means for determining a first set of subframes in the TDD frame structure used for transmitting a downlink control channel to a user equipment (UE), a last subframe in the first set of subframes being subframe n;

means for determining a second set of subframes in the TDD frame structure used for transmitting a downlink data channel to the UE, a first subframe in the second set of subframes being delayed based on k 0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k 0 +x, x being an integer number;

means for signaling first information associated with the k 0 number of subframes to the UE in a first delay field and second information associated with m 0 number of subframes to the UE in a second delay field in a downlink control information (DCI) transmission; and

means for determining an uplink subframe in the TDD frame structure used by the UE for reporting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel, the uplink subframe being delayed the m 0 number of subframes after the subframe n+k 0 x, the m 0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

5. The apparatus of claim 4 , further comprising:

means for receiving a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

6. The apparatus of claim 4 , wherein:

the first information indicates a k 0 number of valid downlink subframes, and

the second information indicates a m 0 number of valid uplink subframes.

7. An apparatus for wireless communications for a base station, comprising:

a memory; and

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

determine a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determine a first set of subframes in the TDD frame structure used for transmitting a downlink control channel to a user equipment (UE), a last subframe in the first set of subframes being subframe n;

determine a second set of subframes in the TDD frame structure used for transmitting a downlink data channel to the UE, a first subframe in the second set of subframes being delayed based on k 0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k 0 x, x being an integer number;

signal first information associated with the k 0 number of subframes to the UE in a first delay field and second information associated with m 0 number of subframes to the UE in a second delay field in a downlink control information (DCI) transmission; and

determine an uplink subframe in the TDD frame structure used by the UE for reporting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel, the uplink subframe being delayed the m 0 number of subframes after the subframe n+k 0 +x, the m 0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

8. The apparatus of claim 7 , wherein the at least one processor is further configured to:

receive a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

9. The apparatus of claim 7 , wherein:

the first information indicates a k 0 number of valid downlink subframes, and

the second information indicates a m 0 number of valid uplink subframes.

10. A non-transitory computer-readable medium storing computer executable code for a base station, comprising code to:

determine a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determine a first set of subframes in the TDD frame structure used for transmitting a downlink control channel to a user equipment (UE), a last subframe in the first set of subframes being subframe n;

determine a second set of subframes in the TDD frame structure used for transmitting a downlink data channel to the UE, a first subframe in the second set of subframes being delayed based on k 0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k 0 +x, x being an integer number;

signal first information associated with the k 0 number of subframes to the UE in a first delay field and second information associated with m 0 number of subframes to the UE in a second delay field in a downlink control information (DCI) transmission; and

determine an uplink subframe in the TDD frame structure used by the UE for reporting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel, the uplink subframe being delayed the m 0 number of subframes after the subframe n+k 0 +x, the m 0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

11. The non-transitory computer-readable medium of claim 10 , further comprising code to:

receive a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

12. The non-transitory computer-readable medium of claim 10 , wherein:

the first information indicates a k 0 number of valid downlink subframes, and

the second information indicates a m 0 number of valid uplink subframes.

13. A method of wireless communications for a user equipment (UE), comprising: determining a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determining a first set of subframes in the TDD frame structure for receiving a downlink control channel from a base station, a last subframe in the first set of subframes being subframe n;

determining a second set of subframes in the TDD frame structure used for receiving a downlink data channel from the base station, a first subframe in the second set of subframes being delayed based on k0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k0+x, x being an integer number;

receiving first information associated with the k0 number of subframes from the base station in a first delay field and second information associated with m0 number of subframes from the base station in a second delay field in a downlink control information (DCI) transmission: and

transmitting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel in an uplink subframe in the TDD frame structure, the uplink subframe being delayed m0 number of subframes after the subframe n+k0+x, the m0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

14. The method of claim 13 , wherein:

the first information indicates a k0 number of valid downlink subframes, and

the second information indicates a m0 number of valid uplink subframes.

15. The method of claim 13 , further comprising:

receiving a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

16. An apparatus for wireless communications at a user equipment (UE), comprising:

means for determining a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

means for determining a first set of subframes in the TDD frame structure for receiving a downlink control channel from a base station, a last subframe in the first set of subframes being subframe n;

means for determining a second set of subframes in the TDD frame structure used for receiving a downlink data channel from the base station, a first subframe in the second set of subframes being delayed based on k0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k0+x, x being an integer number;

means for receiving first information associated with the k0 number of subframes from the base station in a first delay field and second information associated with m0 number of subframes from the base station in a second delay field in a downlink control information (DCI) transmission; and

means for transmitting an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel in an uplink subframe in the TDD frame structure, the uplink subframe being delayed m0 number of subframes after the subframe n+k0+x, the m0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

17. The apparatus of claim 16 , wherein:

the first information indicates a k0 number of valid downlink subframes, and

the second information indicates a m0 number of valid uplink subframes.

18. The apparatus of claim 16 , further comprising:

means for receiving a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

19. An apparatus for wireless communications at a user equipment (UE) comprising:

a memory; and

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

determine a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determine a first set of subframes in the TDD frame structure for receiving a downlink control channel from a base station, a last subframe in the first set of subframes being subframe n;

determine a second set of subframes in the TDD frame structure used for receiving a downlink data channel from the base station, a first subframe in the second set of subframes being delayed based on k0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n+k0+x, x being an integer number;

receive first information associated with the k0 number of subframes from the base station in a first delay field and second information associated with m0 number of subframes from the base station in a second delay field in a downlink control information (DCI) transmission; and

transmit an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel in an uplink subframe in the TDD frame structure, the uplink subframe being delayed m0 number of subframes after the subframe n+k0+x, the m0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

20. The apparatus of claim 19 , wherein:

the first information indicates a k0 number of valid downlink subframes, and

the second information indicates a m0 number of valid uplink subframes.

21. The apparatus of claim 19 , wherein the at least one processor is further configured to:

receive a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.

22. A non-transitory computer-readable medium storing computer executable code for a user equipment (UE), comprising code to:

determine a time-division duplex (TDD) frame structure of a group of TDD frame structures for narrowband communications;

determine a first set of subframes in the TDD frame structure for receiving a downlink control channel from a base station, a last subframe in the first set of subframes being subframe n;

determine a second set of subframes in the TDD frame structure used for receiving a downlink data channel from the base station, a first subframe in the second set of subframes being delayed based on k0 number of subframes after the subframe n, a last subframe in the second set of subframes being subframe n +k0+x, x being an integer number;

receive first information associated with the k0 number of subframes from the base station in a first delay field and second information associated with m0 number of subframes from the base station in a second delay field in a downlink control information (DCI) transmission; and

transmit an acknowledgement (ACK)/negative ACK (NACK) associated with the downlink data channel in an uplink subframe in the TDD frame structure, the uplink subframe being delayed m0 number of subframes after the subframe n +k0+x, the m0 number of subframes including at least one of a number of downlink subframes or a number of uplink subframes.

23. The non-transitory computer-readable of claim 22 , wherein:

the first information indicates a k0 number of valid downlink subframes, and

he second information indicates a m0 number of valid uplink subframes.

24. The non-transitory computer-readable of claim 22 , further comprising code to:

receive a bundle including a plurality of ACK/NACKs from the UE, each ACK/NACK in the bundle being associated with a different hybrid automatic repeat request (HARQ) process.