Methods, systems and apparatus for defining and using PHICH resources for carrier aggregation
Systems, methods, and instrumentalities are disclosed to provide feedback to a user equipment (UE). A UE may transmit uplink data via a supplementary cell. A network device, such as a HeNB, eNB, etc., may receive the uplink data from the UE via the supplementary cell. The network device may send feedback associated with the uplink data to the UE via a physical downlink shared channel (PDSCH) when downlink data is available for transmission to the UE. The feedback may be physical hybrid ARQ indicator channel (PHICH) ACK/NACK information. The feedback sent via the PDSCH may be multiplexed with the downlink data. The network device may send the feedback associated with the uplink data to the UE via a physical downlink control channel (PDCCH) when downlink data is not available for transmission to the UE.
1. A method to provide feedback to a user equipment (UE), the method comprising:
allocating resources for providing feedback to the UE on a licensed band;
receiving uplink data from the UE via a supplementary cell that uses an unlicensed band;
increasing the allocated resources in response to receiving the uplink data via the supplementary cell;
determining a downlink channel on the licensed band for sending feedback associated with the uplink data based on whether downlink data is available for transmission to the UE, wherein the feedback is determined to be sent to the UE via a Physical Downlink Shared Channel (PDSCH) when the downlink data is available for transmission to the UE, and the feedback is determined to be sent to the UE via a Physical Downlink Control Channel (PDCCH) when the downlink data is not available for transmission to the UE; and
sending the feedback via the determined channel, wherein when the feedback is sent via the PDSCH, the feedback is multiplexed with the downlink data, and wherein when the feedback is sent via the PDCCH, the feedback is sent via a DCI format on the PDCCH, a modulation and encoding value being associated with the DCI format that indicates that the DCI format comprises ACK/NACK information.
2. The method of claim 1 , wherein the ACK/NACK information associated with the feedback is sent in a resource block assignment.
3. The method of claim 2 , wherein the resource block assignment is a single resource block using a type 2 allocation.
4. The method of claim 1 , wherein the DCI format is format 1C associated with the PDCCH.
5. The method of claim 1 , wherein the feedback is sent on a primary component carrier.
6. The method of claim 1 , wherein the feedback is sent on a licensed cell.
7. A network device configured to provide feedback to a user equipment (UE), the network device comprising:
a processor configured to:
allocate resources for providing feedback to the UE on a licensed band;
receive uplink data from the UE via a supplementary cell that uses an unlicensed band;
increase the allocated resources in response to receiving the uplink data via the supplementary cell;
determine a downlink channel on the licensed band for sending feedback associated with the uplink data based on whether downlink data is available for transmission to the UE, wherein the feedback is determined to be sent to the UE via a Physical Downlink Shared Channel (PDSCH) when the downlink data is available for transmission to the UE, and the feedback is determined to be sent to the UE via a Physical Downlink Control Channel (PDCCH) when the downlink data is not available for transmission to the UE; and
send the feedback via the determined channel, wherein when the feedback is sent via the PDSCH, the feedback is multiplexed with the downlink data, and wherein when the feedback is sent via the PDCCH, the feedback is sent via a DCI format on the PDCCH, a modulation and encoding value being associated with the DCI format that indicates that the DCI format comprises ACK/NACK information.
8. The network device of claim 7 , wherein the ACK/NACK information associated with the feedback is sent in a resource block assignment.
9. The network device of claim 8 , wherein the resource block assignment is a single resource block using a type 2 allocation.
10. The network device of claim 7 , wherein the DCI format is format 1C associated with the PDCCH.
11. The network device of claim 7 , wherein the feedback is sent on a primary component carrier.
12. The network device of claim 7 , wherein the feedback is sent on a licensed cell.