Method and apparatus for scheduling uplink transmissions with reduced latency

1. A method comprising:

computing, at a device, a first type of power headroom report based on transmission of only a first transmit time interval length in a subframe;

computing a second type of power headroom report based on transmission of both the first transmit time interval length and a second transmit time interval length in the subframe; and

transmitting the first type of power headroom report and the second type of power headroom report.

2. The method according to claim 1 , wherein computing the first type of power headroom report comprises computing the first type of power headroom report based on transmission of only the first transmit time interval length in the subframe even if transmission of the first transmit time interval length and transmission of the second transmit time interval length are in the subframe.

3. The method according to claim 2 , wherein computing the first type of power headroom report comprises computing the first type of power headroom report based on a configured maximum transmit power value based on the transmission of only the first transmit time interval length in the subframe.

4. The method according to claim 3 , wherein computing the first type of power headroom report comprises computing the first type of power headroom report based on a configured maximum transmit power value based on transmission of only the first transmit time interval length in the subframe even if transmission of the first transmit time interval length and transmission of the second transmit time interval length are in the subframe.

5. The method according to claim 1 , wherein computing the second type of power headroom report comprises computing the second type of power headroom report based on transmission of both the first transmit time interval length and the second transmit time interval length in the subframe even if transmission of only one of the first transmit time interval length and the second transmit time interval length is in the subframe.

6. The method according to claim 5 , wherein computing the second type of power headroom report comprises computing the second type of power headroom report based on a fixed resource block allocation and a fixed transmit power control command value if the transmission of the second transmit time interval length is not in the subframe.

7. The method according to claim 1 ,

wherein computing the first type of power headroom report comprises computing the first type of power headroom report based on a first set of higher layer configured power control parameters associated with the first transmit time interval length, where the higher layer is higher than a physical layer, and

wherein computing the second type of power headroom report comprises computing the second type of power headroom report based on the first set of higher layer configured power control parameters associated with the first transmit time interval length and a second set of higher layer configured power control parameters associated with the second transmit time interval length.

8. The method according to claim 1 , wherein computing at least one selected from the first type of power headroom report and the second type of power headroom report further comprises computing the power headroom report based on a transmission of only a first type of physical channel in the subframe, wherein the first type of physical channel is a physical uplink shared channel.

9. The method according to claim 1 , wherein computing at least one selected from the first type of power headroom report and the second type of power headroom report further comprises computing the power headroom report based on at least two types of physical channels in the subframe, where a first type of physical channel of the at least two types is a physical uplink shared channel and a second type of physical channel of the at least two types is a physical uplink control channel.

10. The method according to claim 1 ,

wherein computing the second type of power headroom report further comprises computing the second type of power headroom report based on a fixed resource block allocation and a fixed transmit power control command value for the transmission of the second transmit time interval length, and

wherein transmitting the second type of power headroom report further comprises transmitting the second type of power headroom report in the subframe using a physical channel transmission of the first transmit time interval length, wherein the second transmit time interval length is shorter than the first transmit time interval length.

11. The method according to claim 1 ,

wherein computing the second type of power headroom report further comprises computing the second type of power headroom report based on a resource block allocation and a transmit power control command value received in a uplink grant for the physical channel transmission of the second transmit time interval length, and

wherein transmitting the second type of power headroom report further comprises transmitting the second type of power headroom report in the subframe using a physical channel transmission of the second transmit time interval length, wherein the second transmit time interval length is shorter than the first transmit time interval length.

12. The method according to claim 1 , wherein the first transmit time interval length is different from the second transmit time interval length.

13. The method according to claim 1 , wherein computing the first type of power headroom report comprises computing the first type of power headroom report assuming transmission of only a first transmit time interval length in a subframe.

14. An apparatus comprising:

a controller that

computes a first type of power headroom report based on transmission of only a first transmit time interval length in a subframe, and

computes a second type of power headroom report based on transmission of both the first transmit time interval length and a second transmit time interval length in the subframe; and

a transceiver that transmits the first type of power headroom report and the second type of power headroom report.

15. The apparatus according to claim 14 , wherein the controller computes the first type of power headroom report based on transmission of only the first transmit time interval length in the subframe even if transmission of the first transmit time interval length and transmission of the second transmit time interval length are in the subframe.

16. The apparatus according to claim 15 , wherein the controller computes the second type of power headroom report based on transmission of both the first transmit time interval length and a second transmit time interval length in the subframe even if transmission of only one of the first transmit time interval length and the second transmit time interval length are in the subframe.

17. The apparatus according to claim 16 , wherein the controller computes the second type of power headroom report based on a fixed resource block allocation and a fixed transmit power control command value if the transmission of the second transmit time interval length is not in the subframe.

18. The apparatus according to claim 12 , wherein the controller computes the first type of power headroom report based on a first set of higher layer configured power control parameters associated with the first transmit time interval length, where the higher layer is higher than a physical layer, and

wherein the controller computes the second type of power headroom report based on the first set of higher layer configured power control parameters associated with the first transmit time interval length and a second set of higher layer configured power control parameters associated with the second transmit time interval length.

19. The apparatus according to claim 12 , wherein the controller computes at least one selected from the first type of power headroom report and the second type of power headroom report by computing the power headroom report based on a transmission of only a first type of physical channel in the subframe, wherein the first type of physical channel is a physical uplink shared channel.

20. The apparatus according to claim 14 , wherein the controller computes at least one selected from the first type of power headroom report and the second type of power headroom report by computing the power headroom report based on at least two types of physical channels in the subframe, where a first type of physical channel of the at least two types is a physical uplink shared channel and a second type of physical channel of the at least two types is a physical uplink control channel.

21. The apparatus according to claim 14 ,

wherein the controller computes the second type of power headroom report based on a fixed resource block allocation and a fixed transmit power control command value for the transmission of the second transmit time interval length, and

wherein the transceiver transmits the second type of power headroom report in the subframe using a physical channel transmission of the first transmit time interval length, wherein the second transmit time interval length is shorter than the first transmit time interval length.

22. The apparatus according to claim 14 ,

wherein the controller computes the first type of power headroom report based on a first set of higher layer configured power control parameters associated with the first transmit time interval length, where the higher layer is higher than a physical layer, and

wherein the controller computes the second type of power headroom report based on the first set of higher layer configured power control parameters associated with the first transmit time interval length and a second set of higher layer configured power control parameters associated with the second transmit time interval length.