Methods for dynamic TDD uplink/downlink configuration
A wireless transmit/receive unit (WTRU) may receive a first Time Division Duplex (TDD) uplink (UL)/downlink (DL) configuration. The WTRU may use the first configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ). Further, on a condition that the WTRU receives a second configuration, the WTRU may use the second configuration for DL HARQ and monitor for a third configuration. However, on a condition that the WTRU does not receives a second configuration, the WTRU may use the first configuration for DL HARQ. In addition, on a condition that the third configuration is received by the WTRU, the WTRU may determine a UL or DL direction for a subframe based on the received third configuration. On a condition that the third configuration is not received by the WTRU, the WTRU may determine a UL or DL direction for the subframe based on the received first 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, wherein the first TDD UL/DL reference configuration is cell-specific;
using, by the WTRU, the received first TDD UL/DL reference configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ);
on a condition that a second TDD UL/DL reference configuration is received by the WTRU, using the received second TDD UL/DL reference configuration for DL HARQ, and monitoring for a third TDD UL/DL reference configuration;
on a condition that the third TDD UL/DL reference configuration is received by the WTRU via physical layer signaling based on the monitoring, determining a UL or DL direction for a subframe based on the received third TDD UL/DL reference configuration;
on a condition that the third TDD UL/DL reference configuration is not received by the WTRU via physical layer signaling based on the monitoring, determining a UL or DL direction for the subframe based on the received first TDD UL/DL reference configuration; and
on a condition that the determined direction for the subframe is DL, receiving, by the WTRU, DL transmissions in the subframe.
2. The method of claim 1 , wherein the third TDD UL/DL reference configuration is received as part of a set of TDD UL/DL reference configurations.
3. The method of claim 2 , further comprising:
receiving, by the WTRU, an indication of an index to the received set of TDD UL/DL reference configurations; and
determining, by the WTRU, the third TDD UL/DL reference configuration based on the received indication of the index.
4. 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).
5. The method of claim 1 , wherein the second TDD UL/DL reference configuration is WTRU-specific.
6. The method of claim 1 , further comprising:
canceling, by the WTRU, a scheduled UL transmission for a specific subframe on a condition that the specific subframe is indicated as DL.
7. The method of claim 1 , further comprising:
on a condition that the third TDD UL/DL reference configuration is not received by the WTRU via physical layer signaling based on the monitoring, blind decoding in a subframe indicated as DL in the first TDD UL/DL reference configuration.
8. The method of claim 1 , wherein the SIB is a SIB 1 .
9. The method of claim 1 , wherein the third TDD UL/DL reference configuration is received as part of downlink control information (DCI).
10. The method of claim 1 , wherein the third TDD UL/DL reference configuration is WTRU-specific.
11. A wireless transmit/receive unit (WTRU) for Time Division Duplex (TDD) operation, the WTRU comprising:
a transceiver; and
a processor operatively coupled to the transceiver, wherein the transceiver and the processor are configured to receive, via a system information block (SIB), a first TDD uplink (UL)/downlink (DL) reference configuration, wherein the first TDD UL/DL reference configuration is cell-specific;
wherein the transceiver and the processor are configured to use the received first TDD UL/DL reference configuration for timing of UL scheduling and UL Hybrid Automatic Repeat Request (HARQ);
wherein on a condition that a second TDD UL/DL reference configuration is received by the transceiver and the processor, the transceiver and the processor are configured to use the received second TDD UL/DL reference configuration for DL HARQ, and monitoring for a third TDD UL/DL reference configuration;
wherein on a condition that the third TDD UL/DL reference configuration is received by the transceiver and the processor via physical layer signaling based on the monitoring, the transceiver and the processor are 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 third TDD UL/DL reference configuration is not received by the transceiver and the processor via physical layer signaling based on the monitoring, the transceiver and the processor are configured to determine a UL or DL direction for the subframe based on the received first TDD UL/DL reference configuration; and
wherein on a condition that the determined direction for the subframe is DL, the transceiver and the processor are configured to receive DL transmissions in the subframe.
12. The WTRU of claim 11 , wherein the third TDD UL/DL reference configuration is received as part of a set of TDD UL/DL reference configurations.
13. The WTRU of claim 12 , further comprising:
the transceiver and the processor configured to receive an indication of an index to the set of TDD UL/DL reference configurations; and
the transceiver and the processor configured to determine the third TDD UL/DL reference configuration based on the received indication of the index.
14. The WTRU of claim 11 , 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).
15. The WTRU of claim 11 , wherein the second TDD UL/DL reference configuration is WTRU-specific.
16. The WTRU of claim 11 , further comprising:
the transceiver and the processor configured to cancel a scheduled UL transmission for a specific subframe on a condition that the specific subframe is indicated as DL.
17. The WTRU of claim 11 , further comprising
on a condition that the third TDD UL/DL reference configuration is not received by the transceiver and the processor via physical layer signaling based on the monitoring, blind decoding in a subframe indicated as DL in the first TDD UL/DL reference configuration.
18. The WTRU of claim 11 , wherein the SIB is a SIB 1 .
19. The WTRU of claim 11 , wherein the third TDD UL/DL reference configuration is received as part of downlink control information (DCI).
20. The WTRU of claim 11 , wherein the third TDD UL/DL reference configuration is WTRU-specific.
21. A wireless transmit/receive unit (WTRU) for transmission and reception operations, the WTRU comprising:
a transceiver operatively coupled to a processor, the transceiver and the processor configured to receive, a first uplink (UL)/downlink (DL) reference configuration, wherein the first UL/DL reference configuration is cell-specific;
the processor configured to determine a UL direction or a DL direction for time units in a first set of time units based on the received first UL/DL reference configuration;
the transceiver and the processor configured to receive a second UL/DL reference configuration;
the processor configured to determine a UL direction or a DL direction for time units in a second set of time units based on the received second UL/DL reference configuration;
the transceiver and the processor configured to receive a third UL/DL reference configuration, wherein at least one of the second UL/DL reference configuration and the third UL/DL reference configuration is WTRU-specific;
the processor configured to determine a UL direction or a DL direction for time units in a third set of time units based on the received third UL/DL reference configuration; and
on a condition that the determined direction for a time unit is DL, the transceiver and the processor configured to receive DL transmissions in the time unit.
22. The WTRU of claim 21 , wherein the receiving DL transmissions in the time unit 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).
23. The WTRU of claim 21 , wherein the first UL/DL reference configuration is cell-specific.
24. The WTRU of claim 21 , wherein at least one of the second UL/DL reference configuration and the third UL/DL reference configuration is WTRU-specific.
25. The WTRU of claim 21 , further comprising:
the processor configured to cancel a scheduled UL transmission for a specific time unit on a condition that the specific time unit is indicated as DL.
26. The WTRU of claim 21 , wherein the first UL/DL reference configuration is received via a system information block (SIB).
27. The WTRU of claim 21 , wherein at least one of the first UL/DL reference configuration and the second UL/DL reference configuration is received via higher layer signaling.
28. The WTRU of claim 21 , wherein the third UL/DL reference configuration is received via physical layer signaling.
29. The WTRU of claim 21 , wherein on a condition that the determined direction for the a time unit is UL the transceiver and the processor configured to transmit UL transmissions in the time unit.
30. The WTRU of claim 21 , further comprising:
the transceiver and the processor configured to receive a fourth UL/DL reference configuration.