Coverage enhancement for time division duplex and enhanced interference mitigation and traffic adaptation in long term evolution systems
Methods and systems are disclosed for use by a wireless transmit/receive unit (WTRU) operating in a coverage enhanced (CE) or coverage enhancement mode. The WTRU may receive a first Time Division Duplex (TDD) uplink (UL)/downlink (DL) subframe configuration and may receive a second TDD UL/DL subframe configuration. The WTRU may determine one or more subframes to use for receiving DL repetitions based on the first TDD UL/DL subframe configuration, and one or more subframes to use for transmitting UL repetitions based on the second TDD UL/DL subframe configuration. The WTRU may receive DL repetitions of a DL signal only in the determined one or more subframes for receiving DL repetitions, and may transmit UL repetitions of a UL signal only in the determined one or more subframes for transmitting UL repetitions. The WTRU may receive a TDD transmission using enhanced Interference Mitigation and Traffic Adaptation (eIMTA) capability.
1. A method for use in a wireless transmit/receive unit (WTRU) using coverage enhancement in Time Division Duplex (TDD), the method comprising:
receiving, by the WTRU, a TDD uplink (UL)/downlink (DL) subframe configuration;
receiving, by the WTRU, a subframe restriction indication;
determining, by the WTRU, based on both the received TDD UL/DL subframe configuration and the received subframe restriction indication, one or more subframes to use for receiving DL repetitions and one or more subframes to use for transmitting UL repetitions;
receiving, by the WTRU, DL repetitions of a DL signal only in the determined one or more subframes to use for receiving DL repetitions; and
transmitting, by the WTRU, UL repetitions of a UL signal only in the determined one or more subframes to use for transmitting UL repetitions.
2. The method of claim 1 , wherein the WTRU is an enhanced Interference Mitigation and Traffic Adaptation (eIMTA)-WTRU.
3. The method of claim 1 , wherein the determination of the one or more subframes to use for receiving DL repetitions is based on respective one or more DL subframes of the TDD UL/DL subframe configuration.
4. The method of claim 1 , wherein the determination of the one or more subframes to use for receiving DL repetitions is based on respective one or more DL subframes and special subframes of the TDD UL/DL subframe configuration.
5. The method of claim 1 , wherein the subframe restriction indication is a subframe subset restriction indication.
6. The method of claim 1 , wherein the determination of the one or more subframes to use for transmitting UL repetitions results in a determination of one or more restricted UL subframes not to use for transmitting UL repetitions.
7. The method of claim 1 , wherein the TDD UL/DL subframe configuration is indicated in a broadcast channel and the subframe restriction indication is indicated in a bit map in a WTRU-specific radio resource control (RRC) signaling.
8. The method of claim 1 , wherein the TDD UL/DL subframe configuration and the subframe restriction indication are indicated in a broadcast channel received by the WTRU in a coverage enhanced mode of operation.
9. A wireless transmit/receive unit (WTRU) using coverage enhancement in Time Division Duplex (TDD), the WTRU comprising:
a receiver;
a processor operatively coupled to the receiver; and
a transmitter operatively coupled to the processor;
wherein the receiver is configured to receive a TDD uplink (UL)/downlink (DL) subframe configuration;
wherein the receiver is further configured to receive a subframe restriction indication;
wherein the processor is configured to determine, based on both the received TDD UL/DL subframe configuration and the received subframe restriction indication, one or more subframes to use for receiving DL repetitions and one or more subframes to use for transmitting UL repetitions;
wherein the receiver is further configured to receive DL repetitions of a DL signal only in the determined one or more subframes to use for receiving DL repetitions; and
wherein the transmitter is configured to transmit UL repetitions of a UL signal only in the determined one or more subframes to use for transmitting UL repetitions.
10. The WTRU of claim 9 , wherein the WTRU is an enhanced Interference Mitigation and Traffic Adaptation (eIMTA)-WTRU.
11. The WTRU of claim 9 , wherein the determination of the one or more subframes to use for receiving DL repetitions is based on respective one or more DL subframes of the TDD UL/DL subframe configuration.
12. The WTRU of claim 9 , wherein the determination of the one or more subframes to use for receiving DL repetitions is based on respective one or more DL subframes and special subframes of the TDD UL/DL subframe configuration.
13. The WTRU of claim 9 , wherein the subframe restriction indication is a subframe subset restriction indication.
14. The WTRU of claim 9 , wherein the determination of the one or more subframes to use for transmitting UL repetitions results in a determination of one or more restricted UL subframes not to use for transmitting UL repetitions.
15. The WTRU of claim 9 , wherein the TDD UL/DL subframe configuration is indicated in a broadcast channel and the subframe restriction indication is indicated in a bit map in a WTRU-specific radio resource control (RRC) signaling.
16. The WTRU of claim 9 , wherein the TDD UL/DL subframe configurations and the subframe restriction indication are indicated in a broadcast channel received by the WTRU in a coverage enhanced mode of operation.