Method of handling uplink/downlink configurations for time-division duplexing system and related communication device

1. A method of handling an uplink/downlink (UL/DL) configuration for a communication device which supports Enhanced Interference Mitigation and Traffic Adaptation (eIMTA) function, the method comprising:

receiving a first cell-specific UL/DL configuration in first system information from a first cell in an idle mode;

applying the first cell-specific UL/DL configuration in the first system information;

receiving a second user-equipment-specific UL/DL configuration on a physical DL control channel from the first cell in a connected mode;

applying the second user-equipment-specific UL/DL configuration on the physical DL control channel instead of the first cell-specific UL/DL configuration in the first system information;

receiving a third cell-specific UL/DL configuration in second system information from the first cell in the connected mode;

applying the third cell-specific UL/DL configuration in the second system information instead of the second user-equipment-specific UL/DL configuration on the physical DL control channel, when the first cell-specific UL/DL configuration in the first system information and the third cell-specific UL/DL configuration in the second system information are different; and

keeping applying the second user-equipment-specific UL/DL configuration on the physical DL control channel, when the first cell-specific UL/DL configuration in the first system information and the third cell-specific UL/DL configuration in the second system information are the same.

2. The method of claim 1 , wherein the step of receiving the third cell-specific UL/DL configuration in the second system information from the first cell in the connected mode comprises:

performing a radio resource control (RRC) connection reestablishment procedure; and

receiving the third cell-specific UL/DL configuration in the second system information from the first cell when performing the RRC connection reestablishment procedure.

3. The method of claim 2 , further comprising:

releasing the second user-equipment-specific UL/DL configuration on the physical DL control channel when the RRC connection reestablishment procedure is triggered.

4. The method of claim 1 , wherein the step of receiving the second user-equipment-specific UL/DL configuration on the physical DL control channel from the first cell in the connected mode comprises:

receiving a message comprising an enhanced interference management & traffic adaptation (eIMTA) configuration; and

receiving the second user-equipment-specific UL/DL configuration on the physical DL control channel according to the eIMTA configuration in the connected mode.

5. The method of claim 4 , wherein the eIMTA configuration comprises a radio network temporary identifier (RNTI) for receiving the second user-equipment-specific UL/DL configuration on the physical DL control channel.

6. The method of claim 4 , further comprising:

releasing the eIMTA configuration after applying the third cell-specific UL/DL configuration in the second system information.

7. A method of handling an uplink/downlink (UL/DL) configuration for a communication device which supports Enhanced Interference Mitigation and Traffic Adaptation (eIMTA) function, the method comprising:

receiving a first cell-specific UL/DL configuration in first system information from a first cell in an idle mode;

applying the first cell-specific UL/DL configuration in the first system information;

receiving a second user-equipment-specific UL/DL configuration on a physical DL control channel from the first cell in a connected mode;

applying the second user-equipment-specific UL/DL configuration on the physical DL control channel instead of the first cell-specific UL/DL configuration in the first system information;

performing a radio resource control (RRC) connection reestablishment procedure with the first cell when detecting at least one of a radio link failure, an integrity check failure and an RRC connection reconfiguration failure; and

applying the first cell-specific UL/DL configuration in the first system information instead of the second user-equipment-specific UL/DL configuration on the physical DL control channel when performing the RRC connection reestablishment procedure with the first cell.

8. The method of claim 7 , wherein the step of applying the first cell-specific UL/DL configuration in the first system information when performing the RRC connection reestablishment procedure with the first cell comprises:

determining whether a first value tag of the first system information is equal to a second value tag broadcasted by the first cell when performing the RRC connection reestablishment procedure with the first cell; and

applying the first cell-specific UL/DL configuration in the first system information when the first value tag is equal to the second value tag.

9. The method of claim 8 , further comprising:

receiving a second system information when the first value tag is different from the second value tag; and

applying a third cell-specific UL/DL configuration of the second system information.

10. The method of claim 7 , wherein the step of receiving the second user-equipment-specific UL/DL configuration on the physical DL control channel from the first cell comprises:

receiving a message with an enhanced interference management & traffic adaptation (eIMTA) configuration; and

receiving the second user-equipment-specific UL/DL configuration in the physical DL control channel according to the eIMTA configuration.

11. The method of claim 10 , wherein the eIMTA configuration comprises a radio network temporary identifier (RNTI) for receiving the second user-equipment-specific UL/DL configuration on the physical DL control channel.

12. The method of claim 10 , further comprising:

releasing the eIMTA configuration after applying the first cell-specific UL/DL configuration in the first system information.

13. A communication device which supports Enhanced Interference Mitigation and Traffic Adaptation (eIMTA) function and is utilized for a wireless communication system, comprising:

a processing means; and

a storage unit, coupled to the processing means, for storing a program code, wherein the program code instructs the processing means to execute the following step:

receiving a first cell-specific UL/DL configuration in first system information from a first cell in an idle mode;

applying the first cell-specific UL/DL configuration in the first system information;

receiving a second user-equipment-specific UL/DL configuration on a physical DL control channel from the first cell in a connected mode;

applying the second user-equipment-specific UL/DL configuration on the physical DL control channel instead of the first cell-specific UL/DL configuration;

receiving a third cell-specific UL/DL configuration in second system information from the first cell in the connected mode;

applying the third cell-specific UL/DL configuration in the second system information instead of the second user-equipment-specific UL/DL configuration on the physical DL control channel, when the first cell-specific UL/DL configuration in the first system information and the third cell-specific UL/DL configuration in the second system information are different; and

keeping applying the second user-equipment-specific UL/DL configuration on the physical DL control channel, when the first cell-specific UL/DL configuration in the first system information and the third cell-specific UL/DL configuration in the second system information are the same.

14. The communication device of claim 13 , wherein the step of receiving the third cell-specific UL/DL configuration in the second system information from the first cell in the connected mode comprises:

performing a radio resource control (RRC) connection reestablishment procedure; and

receiving the third cell-specific UL/DL configuration in the second system information from the first cell when performing the RRC connection reestablishment procedure.