Methods for dynamic TDD uplink/downlink configuration

1. A method for Time Division Duplex (TDD) operation in a wireless transmit/receive unit (WTRU), the method comprising:

receiving, by the WTRU via a system information block (SIB), a first TDD uplink (UL)/downlink (DL) reference configuration for a serving cell, wherein the first TDD UL/DL reference configuration is cell-specific;

receiving, by the WTRU, a second TDD UL/DL reference configuration for the serving cell;

receiving, by the WTRU via physical layer signaling, a third TDD UL/DL reference configuration for the serving cell;

using, by the WTRU, the received first TDD UL/DL reference configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ);

using, by the WTRU, the received second TDD UL/DL reference configuration for timing of DL HARQ; and

determining, by the WTRU, a UL or DL direction for a subframe based on the received third TDD UL/DL reference configuration;

wherein on a condition that the determined direction for the subframe is DL, receiving DL transmissions in the subframe.

2. The method of claim 1 , wherein the receiving DL transmissions in the subframe includes at least one of monitoring a Physical Downlink Control Channel (PDCCH), monitoring an enhanced PDCCH (EPDCCH), decoding a Physical Hybrid Automatic Repeat Request (ARQ) Indicator Channel (PHICH), and decoding a Physical Downlink Shared Channel (PDSCH).

3. The method of claim 1 , wherein the second TDD UL/DL reference configuration is WTRU-specific.

4. The method of claim 1 , further comprising:

cancelling, by the WTRU, a scheduled UL transmission for a specific subframe on a condition that the specific subframe is indicated as DL.

5. The method of claim 1 , wherein the SIB is a SIB1.

6. The method of claim 1 , wherein on a condition that the WTRU does not receive the third TDD UL/DL reference configuration, the WTRU performs blind decoding in a subframe indicated as DL in the first TDD UL/DL reference configuration.

7. The method of claim 6 , wherein blind decoding includes monitoring at least one of a Physical Downlink Control Channel (PDCCH) and an enhanced PDCCH (EPDCCH).

8. The method of claim 6 , wherein blind decoding is not performed in a subframe in which the WTRU has a scheduled UL transmission and the WTRU transmits as scheduled in the subframe.

9. The method of claim 6 , wherein the WTRU receives a Physical Hybrid ARQ Indicator Channel (PHICH) in a subframe in which a PHICH intended for the WTRU is expected by the WTRU.

10. The method of claim 1 , wherein the third TDD UL/DL reference configuration is WTRU-specific.

11. The method of claim 1 , wherein the third TDD UL/DL reference configuration is received in a current reconfiguration period; and

wherein the determination of the UL or DL direction is determined for at least one subframe of the current reconfiguration period and a plurality of subframes of a next reconfiguration period.

12. The method of claim 11 , wherein the reconfiguration period occurs periodically.

13. The method of claim 1 , further comprising:

on a condition that the third TDD UL/DL reference configuration is not received in a reconfiguration period, blind decoding, by the WTRU, in a subframe indicated as a DL subframe in the first TDD UL/DL configuration.

14. The method of claim 11 , wherein the reconfiguration period is a radio frame.

15. A method for Time Division Duplex (TDD) in an evolved Node B (eNB), the method comprising:

transmitting, by the eNB via a system information block (SIB), a first TDD uplink (UL)/downlink (DL) reference configuration for a cell, wherein the first TDD UL/DL reference configuration is cell-specific;

transmitting, by the eNB, a second TDD UL/DL reference configuration for the cell to at least one WTRU;

transmitting, by the eNB via physical layer signaling, a third TDD UL/DL reference configuration for the cell to the at least one WTRU;

using, by the eNB, for the at least one WTRU the first TDD UL/DL reference configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ);

using, by the eNB, for the at least one WTRU the second UL/DL reference configuration for timing of DL HARQ; and

transmitting, by the eNB, DL transmissions in at least one subframe which is DL in the third TDD UL/DL reference configuration.

16. The method of claim 15 , wherein the eNB uses the first TDD UL/DL reference configuration for both the UL and DL scheduling and HARQ operations for at least one other WTRU.

17. The method of claim 15 , wherein the second TDD UL/DL reference configuration is WTRU-specific.

18. The method of claim 15 , wherein the third TDD UL/DL reference configuration is WTRU-specific.

19. The method of claim 15 , wherein the third TDD UL/DL reference configuration is transmitted in a current reconfiguration period; and

wherein the determination of the UL or DL direction is determined for at least one subframe of the current reconfiguration period and a plurality of subframes of a next reconfiguration period.

20. The method of claim 15 , wherein the SIB is a SIB 1 .

21. The method of claim 19 , wherein the reconfiguration period occurs periodically.

22. The method of claim 19 , wherein the reconfiguration period is a radio frame.

23. A wireless transmit/receive unit (WTRU) for Time Division Duplex (TDD) operation comprising:

a transceiver operatively coupled to a processor, the transceiver and the processor configured to receive, via a system information block (SIB), a first TDD uplink (UL)/downlink (DL) reference configuration for a serving cell, wherein the first TDD UL/DL reference configuration is cell-specific;

the transceiver and the processor further configured to receive a second TDD UL/DL reference configuration for the serving cell;

the transceiver and the processor further configured to receive, via physical layer signaling, a third TDD UL/DL reference configuration for the serving cell;

the transceiver and the processor further configured to use the received first TDD UL/DL reference configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ);

the transceiver and the processor further configured to use the received second TDD UL/DL reference configuration for timing of DL HARQ; and

the transceiver and the processor further configured to determine a UL or DL direction for a subframe based on the received third TDD UL/DL reference configuration;

wherein on a condition that the determined direction for the subframe is DL, the transceiver and the processor further configured to receive DL transmissions in the subframe.

24. The WTRU of claim 23 , wherein to receive DL transmissions in the subframe includes at least one of monitoring a Physical Downlink Control Channel (PDCCH), monitoring an enhanced PDCCH (EPDCCH), decoding a Physical Hybrid Automatic Repeat Request (ARQ) Indicator Channel (PHICH), and decoding a Physical Downlink Shared Channel (PDSCH).

25. The WTRU of claim 23 , wherein the second TDD UL/DL reference configuration is WTRU-specific.

26. The WTRU of claim 23 , wherein the third TDD UL/DL reference configuration is WTRU-specific.

27. The WTRU of claim 23 , wherein the third TDD UL/DL reference configuration is received in a current reconfiguration period; and

wherein the determination of the UL or DL direction is determined for at least one subframe of the current reconfiguration period and a plurality of subframes of a next reconfiguration period.

28. The WTRU of claim 27 , wherein the reconfiguration period occurs periodically.

29. The WTRU of claim 27 , wherein the reconfiguration period is a radio frame.

30. The WTRU of claim 23 , wherein the SIB is a SIB 1 .