Method and apparatus for signaling different short TTI (transmission time interval) band in shortened TTI in a wireless communication system
A method and apparatus are disclosed from the perspective of a first UE. In one embodiment, the method includes a first UE configured with TTI(s) shorter than one subframe; wherein there are X TTIs in one subframe. The method further includes the first UE receiving a downlink control information which indicates resource allocation for first resources and second resources; wherein there are X TTIs in the first resources.
1. A method of a first UE (User Equipment), comprising:
the first UE is configured with TTI(s) (Transmission Time Interval) shorter than one subframe, wherein there are X TTIs in one subframe and X is an integer larger than one;
the first UE receives a DCI (Downlink Control Information) which indicates resource allocation for first resources and second resources, wherein there are X TTIs in the first resources and there are Y TTIs in the second resources, and wherein Y is an integer larger than one and is different than X.
2. The method of claim 1 , further comprising:
a second UE is configured with a TTI shorter than one subframe, wherein there are Y TTIs in one subframe;
the second UE receives the downlink control information which indicates resource allocation for the first resources and the second resources, wherein there are X TTIs in the first resources and there are Y TTIs in the second resources.
3. The method of claim 2 , wherein the first UE and the second UE configured by a RNTI (Radio Network Temporary Identifier) value, wherein the RNTI value is used to monitor the downlink control information.
4. The method of claim 1 , further comprising:
the first UE receives downlink data within the first resources, and does not receive downlink data within the second resources.
5. The method of claim 2 , further comprising:
the second UE receives downlink data within the second resources, and does not receive downlink data within the first resources.
6. The method of claim 1 , wherein the downlink control information indicates common control information for the first resources and the second resources.
7. The method of claim 1 , wherein the downlink control information is transmitted on the control region indicated by CFI (Control Format Indicator) or on the common search space.
8. The method of claim 1 , wherein payload size of the downlink control information is the same as DCI (Downlink Control Information) format size in common search space.
9. The method of claim 1 , wherein the resource allocation field in the downlink control information is converted into a decimal number which represents an unique combination of resource allocation for the first resources and the second resources.
10. The method of claim 9 , wherein the decimal number is sum of extended binomial coefficient of the four indexes.
11. The method of claim 1 , wherein the first resources are allocated to lower frequency PRB(s) (Physical Resource Block) and the second resources are allocated to higher frequency PRB(s).
12. A first User Equipment (UE), comprising:
a control circuit;
a processor installed in the control circuit; and
a memory installed in the control circuit and operatively coupled to the processor;
wherein the processor is configured to execute a program code stored in the memory to:
enable the first UE to be configured with TTI(s) (Transmission Time Interval) shorter than one subframe, wherein there are X TTIs in one subframe and X is an integer larger than one;
receive a DCI (Downlink Control Information) which indicates resource allocation for first resources and second resources, wherein there are X TTIs in the first resources and there are Y TTIs in the second resources, and wherein Y is an integer larger than one and is different from X.
13. The first UE of claim 12 , wherein the processor is configured to execute a program code stored in the memory to:
receive downlink data within the first resources, and does not receive downlink data within the second resources.
14. The first UE of claim 12 , wherein the downlink control information indicates common control information for the first resources and the second resources.
15. The first UE of claim 12 , wherein the downlink control information is transmitted on the control region indicated by CFI (Control Format Indicator) or on the common search space.
16. The first UE of claim 12 , wherein payload size of the downlink control information is the same as DCI (Download Control Information) format size in common search space.
17. The first UE of claim 12 , wherein the first UE and a second UE configured by a RNTI (Radio Network Temporary Identifier) value, wherein the RNTI value is used to monitor the downlink control information.
18. The first UE of claim 12 , wherein the resource allocation field in the downlink control information is converted into a decimal number which represents an unique combination of resource allocation for the first resources and the second resources.
19. The first UE of claim 18 , wherein the decimal number is sum of extended binomial coefficient of the four indexes.
20. The first UE of claim 12 , wherein the first resources are allocated to lower frequency PRB(s) (Physical Resource Block) and the second resources are allocated to higher frequency PRB(s).