Communication units and methods for relay-assisted uplink communication

1. A relay device for supporting uplink communication between a terminal device and a base station, the relay device comprising:

at least one receiver;

a control processor, operably coupled to the at least one receiver and arranged to:

monitor a downlink communication from the base station to the terminal device;

determine therefrom at least one uplink resource to be used by the terminal device;

configure the at least one receiver to receive the at least one uplink resource;

receive an uplink message on the at least one uplink resource;

determine therefrom uplink control information used by the terminal device;

modify the uplink message on the at least one uplink resource; and

relay the uplink message to the base station.

2. The relay device of claim 1 wherein the control processor is arranged to relay the uplink message to the base station as a medium access layer re-transmission.

3. The relay device of claim 1 wherein the control processor is further arranged to determine from the uplink message physical layer signalling used by the terminal device.

4. The relay device of claim 3 wherein the control processor is further arranged to create a relay control element identifying the physical layer signalling.

5. The relay device of claim 4 wherein the relay control element is incorporated into a relayed uplink control information (UCI) message.

6. The relay device of claim 4 wherein the relay control element comprises at least one from a group of:

a terminal device identifier;

signalling radio bearer identifier;

Hybrid Automatic repeat request (HARQ) ACKnowledgement (ACK)/Negative ACKnowledgement length field indication;

HARQ ACK payload;

Channel State Information (CSI) length field indication;

CSI payload.

7. The relay device of claim 3 wherein the physical layer signalling comprises at least one from a group of: ACK/NACK, channel quality information (CQI), Precoding matrix indicator (PMI), rank indicator (RI).

8. The relay device of claim 1 wherein the control processor is further arranged to request an uplink resource from the base station in order to send the relay control element.

9. The relay device of claim 1 wherein the control processor is arranged to monitor a communication from the base station to the terminal device on a physical downlink control channel (PDCCH).

10. The relay device of claim 9 wherein the control processor is arranged to determine from the PDCCH at least one physical uplink control channel (PUCCH) resource from the terminal device.

11. The relay device of claim 1 wherein the control processor is further arranged to modify the uplink message on the at least one uplink resource by identifying the terminal device prior to relaying the uplink message to the base station.

12. The relay device of claim 11 wherein the control processor is arranged to identify the terminal device by incorporating a C-RNTI into a control element of the uplink message.

13. The relay device of claim 11 wherein the control processor is further arranged to package transmitted ACK/NACK information into a control element of the received uplink message.

14. The relay device of claim 13 wherein the relayed uplink message is not associated with periodic transmission from the terminal device.

15. The relay device of claim 11 wherein the control processor is further arranged to determine from the uplink message HARQ ACK/NACK information associated with a previous physical downlink shared channel (PDSCH) transmission.

16. The relay device of claim 11 wherein the control processor is further arranged to determine from the uplink message channel quality information (CQI) associated with a previous physical downlink shared channel (PDSCH) transmission.

17. The relay device of claim 11 wherein the control processor is further arranged to receive an uplink message on the at least one uplink resource after the control processor has monitored a physical downlink shared channel (PDSCH) being used for a communication from the base station to the terminal device.

18. The relay device of claim 1 wherein the control processor is further arranged to configure the at least one receiver to receive the at least one uplink resource; and receive an uplink message on the at least one uplink resource.

19. A wireless communications system comprising the relay device of claim 1 for supporting uplink communication between a terminal device and a base station.

20. An integrated circuit for a relay device for supporting uplink communication between a terminal device and a base station, the integrated circuit comprising a control processor arranged to:

monitor a downlink communication from the base station to the terminal device;

determine therefrom at least one uplink resource to be used by the terminal device;

configure the at least one receiver to receive the at least one uplink resource;

receive an uplink message on the at least one uplink resource;

determine therefrom uplink control information used by the terminal device;

modify the uplink message on the at least one uplink resource; and

relay the uplink message to the base station.

21. A method for supporting wirelessly communication from a terminal device to a base station via a relay device, the method comprising, at the relay device:

monitoring a downlink communication from the base station to the terminal device;

determining therefrom at least one uplink resource to be used by the terminal device;

configuring at least one receiver of the relay device to receive the at least one uplink resource;

receiving an uplink message on the at least one uplink resource;

determining therefrom uplink control information used by the terminal device;

modifying the uplink message on the at least one uplink resource; and

relaying the uplink message to the base station.

22. A non-transitory computer program product comprising executable program code for supporting wirelessly communication from a terminal device to a base station via a relay device, the executable program code operable for, when executed at the relay device, performing the method of claim 21 .