Transmission of uplink control information for link-budget-limited devices

1. A user equipment (UE) device comprising:

at least one antenna;

at least one radio, wherein the at least one radio is configured to communicate with a base station using at least one cellular radio access technology (RAT); and

one or more processors coupled to the at least one radio, wherein the one or more processors and the at least one radio are configured to:

determine that the UE is link budget limited as a result of a hardware limitation of the UE;

based at least in part on the determination, transmit a message to the base station comprising an indication that the UE is link budget limited, wherein the base station is configured to send a first uplink grant to the UE in response to said indication, wherein the base station is configured to transmit first coding rate information in response to said indication, wherein the first coding rate information identifies a first coding rate sufficient to ensure successful decoding of first uplink control information in a physical uplink shared channel (PUSCH), wherein the PUSCH supports channel coding with a flexible coding rate, wherein the base station is configured to receive second uplink control information on a physical uplink control channel (PUCCH) using a defined coding rate in response to an indication that a UE is not link budget limited, wherein the PUCCH is encoded by using Zadoff-Chu sequences, wherein the first coding rate is lower than the defined coding rate;

generate the first uplink control information for transmission to the base station;

receive the first uplink grant from the base station, wherein the first uplink grant identifies uplink resources in the PUSCH for transmission of uplink control information;

apply channel coding to the first uplink control information, wherein the coding rate of the channel coding applied to the first uplink control information is the first coding rate identified by the first coding rate information transmitted by the base station; and

in response to the first uplink grant received from the base station, transmit the first uplink control information to the base station in the PUSCH.

2. The UE device of claim 1 , wherein said one or more processors and the at least one radio are further configured so that said transmitting the message to the base station occurs when the UE device does not have any payload data to transmit.

3. The UE device of claim 1 , wherein the base station is configured to send a sequence of uplink grants to the UE device in response to said message, wherein said first uplink grant is one of the uplink grants of said sequence.

4. The UE device of claim 1 , wherein the first uplink control information comprises channel state information (CSI).

5. The UE device of claim 1 , wherein the one or more processors and the at least one radio are further configured to not transmit uplink traffic data in said PUSCH that is transmitted in response to said first uplink grant.

6. The UE device of claim 1 , wherein the first uplink control information comprises a HARQ acknowledgement message or a HARQ negative acknowledgement message.

7. The UE device of claim 6 , wherein said receiving the first uplink grant from the base station comprises receiving the first uplink grant a predetermined amount of time after receipt of a downlink transmission of downlink traffic data to the UE device from the base station.

8. The UE device of claim 1 , wherein the first uplink grant comprises a persistent uplink grant, wherein the persistent uplink grant lasts for a predetermined period of time or until cancelled, wherein said one or more processors and the at least one radio are configured so that said generating the first uplink control information and said transmitting the PUSCH that includes the first uplink control information are performed a plurality of times utilizing the persistent uplink grant.

9. The UE device of claim 1 , wherein the one or more processors and the at least one radio are further configured to transmit uplink traffic data in the PUSCH that is transmitted in response to said first uplink grant.

10. A method for operating a user equipment (UE) device, the method comprising:

determining that the UE is link budget limited;

based at least in part on said determining, transmitting a message to the base station comprising an indication that the UE is link budget limited, wherein the base station is configured to send an uplink grant to the UE in response to said indication, wherein the base station is configured to transmit first coding rate information in response to said indication, wherein the first coding rate information identifies a first coding rate sufficient to ensure successful decoding of first uplink control information in a physical uplink shared channel (PUSCH), wherein the PUSCH supports channel coding with a flexible coding rate, wherein the base station is configured to receive second uplink control information on a physical uplink control channel (PUCCH) using a defined coding rate in response to an indication that a UE is not link budget limited, wherein the PUCCH is encoded by using Zadoff-Chu sequences, wherein the first coding rate is lower than the defined coding rate;

generating the first uplink control information for transmission to the base station;

receiving the uplink grant from the base station, wherein the uplink grant identifies uplink resources in the PUSCH for transmission of uplink control information;

applying channel coding to the first uplink control information, wherein the coding rate of the channel coding applied to the uplink control information is the first coding rate identified by the coding rate information transmitted by the base station;

in response to the uplink grant received from the base station, transmitting the first uplink control information on the uplink resources in the PUSCH to the base station.

11. The method of claim 10 , further comprising:

receiving downlink traffic data.

12. The method of claim 11 , wherein the uplink grant is received a predetermined amount of time after said reception of the downlink traffic data.

13. The method of claim 11 , wherein a downlink assignment for said at least a portion of the downlink traffic data is received from a physical downlink control channel (PDCCH) of a given downlink subframe, wherein said uplink grant is received from the PDCCH of the same downlink subframe or a later downlink subframe.

14. The method of claim 11 , wherein the first uplink control information includes ACK/NACK for at least a portion of the downlink traffic data.

15. The method of claim 10 , wherein the uplink grant is a persistent uplink grant or a semi-persistent uplink grant.

16. The method of claim 10 , wherein a downlink assignment for said at least a portion of the downlink traffic data is received from a PDCCH of a given downlink subframe, wherein said uplink grant is received from the PDCCH of the same downlink subframe or a later downlink subframe.

17. An apparatus for operating a user equipment device (UE), the apparatus comprising a hardware processing element configured to cause the UE to:

determine that the UE is link budget limited as a result of a hardware limitation of the UE;

based at least in part on the determination, transmit a message to the base station comprising an indication that the UE is link budget limited, wherein the base station is configured to send a first uplink grant to the UE in response to said indication, wherein the base station is configured to transmit first coding rate information in response to said indication, wherein the first coding rate information identifies a first coding rate sufficient to ensure successful decoding of first uplink control information on a physical uplink shared channel (PUSCH), wherein the PUSCH supports channel coding with a flexible coding rate, wherein the base station is configured to receive second uplink control information on a physical uplink control channel (PUCCH) using a defined coding rate in response to an indication that a UE is not link budget limited, wherein the PUCCH is encoded by using Zadoff-Chu sequences, wherein the first coding rate is lower than the defined coding rate;

generate the first uplink control information for transmission to the base station;

receive the first uplink grant from the base station, wherein the uplink grant identifies uplink resources on the PUSCH for transmission of uplink control information;

apply channel coding to the first uplink control information, wherein the coding rate of the channel coding applied to the first uplink control information is the first coding rate identified by the coding rate information transmitted by the base station;

in response to the first uplink grant received from the base station, transmit the first uplink control information on the uplink resources in the PUSCH to the base station.

18. The apparatus of claim 17 , wherein said transmitting the message to the base station occurs when the UE device does not have any payload data to transmit.

19. The apparatus of claim 17 , wherein the base station is configured to send a sequence of uplink grants to the UE device in response to said message, wherein said first uplink grant is one of the uplink grants of said sequence.

20. The apparatus of claim 17 , wherein the first uplink control information comprises channel state information (CSI).

21. The apparatus of claim 17 , wherein the one or more processors and the at least one radio are further configured to not transmit uplink traffic data in said PUSCH that is transmitted in response to said first uplink grant.

22. The apparatus of claim 17 , wherein the first uplink control information comprises a HARQ acknowledgement message or a HARQ negative acknowledgement message.

23. A base station configured to perform wireless communication with a wireless device, the base station comprising:

a radio; and

a processing element operatively coupled to the radio, wherein the radio and the processing element are configured to:

receive a first message comprising a first indication that a user equipment device (UE) is link budget limited, wherein the UE is configured to transmit the first message in response to a determination that the UE is link budget limited as a result of a hardware limitation of the UE;

send a first uplink grant to the UE in response to the first message, wherein the first uplink grant identifies uplink resources in a physical uplink shared channel (PUSCH) for transmission of first uplink control information;

transmit first coding rate information to the UE in response to the first message, wherein the first coding rate information identifies a first coding rate sufficient to ensure successful decoding of first uplink control information in the PUSCH, wherein the PUSCH supports channel coding with a flexible coding rate, wherein the radio and the processing element are configured to receive second uplink control information on a physical uplink control channel (PUCCH) using a defined coding rate in response to an indication that a UE is not link budget limited, wherein the PUCCH is encoded by using Zadoff-Chu sequences, wherein the first coding rate is lower than the defined coding rate; and

receive the first uplink control information from the UE, wherein the first uplink control information is received in the PUSCH, wherein the first uplink control information is channel coded by the UE, wherein the coding rate of the channel coding applied to the first uplink control information is the first coding rate identified by the first coding rate information.

24. The base station of claim 23 , wherein the first uplink control information includes a HARQ acknowledgement message or a HARQ negative acknowledgement message.

25. The base station of claim 23 , wherein the first uplink control information comprises channel state information (CSI).

26. The base station of claim 23 , wherein the first uplink grant comprises a persistent uplink grant, wherein the persistent uplink grant lasts for a predetermined period of time or until cancelled, wherein the radio and the processing element are further configured to:

receive additional uplink control information from one or more additional instances of the PUSCH transmitted from the first UE, wherein the first UE is configured to transmit the one or more additional instances of the PUSCH based on the persistent uplink grant.