Uplink control channel resource allocation for an enhanced downlink control channel of a mobile communication system

1. A method in a user equipment (UE), comprising:

receiving, at the UE, a downlink control channel carrying a physical uplink control channel (PUCCH) resource indicator, wherein the downlink control channel is associated with a demodulation reference signal (DMRS) antenna port;

mapping the PUCCH resource indicator to a first offset;

determining a second offset based on a position of the received downlink control channel normalized by a first value;

determining an index of the DMRS antenna port associated with the downlink control channel;

determining a third offset based on the determined index of the DMRS antenna port;

mapping a linear combination of the first, second, and third offsets to an index identifying a first allocated PUCCH resource; and

transmitting a PUCCH on the first allocated PUCCH resource.

2. The method of claim 1 , wherein the UE receives a plurality of physical downlink shared channel (PDSCHs), respective ones of the PDSCHs being received in respective different subframes, and wherein the mapping of the linear combination comprises adding a first subframe offset corresponding to a first subframe in which a first one of the PDSCHs was received.

3. The method of claim 1 , further comprising:

determining a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

transmitting a PUCCH on one of the first or the second allocated PUCCH resources using a first antenna port.

4. The method of claim 1 , further comprising:

determining a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

transmitting the PUCCH on the first allocated PUCCH resource using a first antenna port and on the second allocated PUCCH resource using a second antenna port, the PUCCH being transmitted simultaneously on the first and second antenna ports.

5. The method of claim 1 , wherein the downlink control channel is in a downlink control information (DCI) format.

6. The method of claim 1 , further comprising:

determining a fourth offset based on a transmission mode of the downlink control channel, wherein the transmission mode is one of localized transmission or distributed transmission; and

mapping a linear combination of the first, second, third, and fourth offsets to the index identifying the first allocated PUCCH resource.

7. The method of claim 1 , wherein the first value is a number of enhanced control channel elements (eCCEs).

8. The method of claim 7 , wherein determining the second offset comprises determining the largest integer that is smaller than or equal to the position of the received downlink control channel normalized by the first value.

9. The method of claim 1 , wherein the first value is a length of enhanced physical downlink control channel (ePDCCH).

10. A user equipment (UE), comprising:

a memory; and

at least one hardware processor communicatively coupled with the memory and configured to:

receive a downlink control channel carrying a physical uplink control channel (PUCCH) resource indicator, wherein the downlink control channel is associated with a demodulation reference signal (DMRS) antenna port;

map the PUCCH resource indicator to a first offset;

determine a second offset based on a position of the received downlink control channel normalized by a first value;

determine an index of the DMRS antenna port associated with the downlink control channel;

determine a third offset based on the determined index of the DMRS antenna port;

map a linear combination of the first, second, and third offsets to an index identifying a first allocated PUCCH resource; and

transmit a PUCCH on the first allocated PUCCH resource.

11. The UE of claim 10 , wherein the UE receives a plurality of physical downlink shared channel (PDSCHs), respective ones of the PDSCHs being received in respective different subframes, and wherein the mapping of the linear combination comprises adding a first subframe offset corresponding to a first subframe in which a first one of the PDSCHs was received.

12. The UE of claim 10 , wherein the at least one hardware processor is further configured to:

determine a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

transmit a PUCCH on one of the first or the second allocated PUCCH resources using a first antenna port.

13. The UE of claim 10 , wherein the at least one hardware processor is further configured to:

determine a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

transmit the PUCCH on the first allocated PUCCH resource using a first antenna port and on the second allocated PUCCH resource using a second antenna port, the PUCCH being transmitted simultaneously on the first and second antenna ports.

14. The UE of claim 10 , wherein the downlink control channel is in a downlink control information (DCI) format.

15. The UE of claim 10 , wherein the at least one hardware processor is further configured to:

determine a fourth offset based on a transmission mode of the downlink control channel, wherein the transmission mode is one of localized transmission or distributed transmission; and

map a linear combination of the first, second, third, and fourth offsets to the index identifying the first allocated PUCCH resource.

16. The UE of claim 10 , wherein the first value is a number of enhanced control channel elements (eCCEs).

17. The UE of claim 16 , wherein determining the second offset comprises determining the largest integer that is smaller than or equal to the position of the received downlink control channel normalized by the first value.

18. The UE of claim 10 , wherein the first value is a length of enhanced physical downlink control channel (ePDCCH).

19. A method in an access node, comprising:

transmitting, to a user equipment (UE), a downlink control channel carrying a PUCCH resource indicator, wherein the downlink control channel is transmitted using a demodulation reference signal (DMRS) antenna port;

mapping the PUCCH resource indicator to a first offset;

determining a second offset based on a position of the transmitted downlink control channel normalized by a first value;

determining a third offset based on an index of the DMRS antenna port used to transmit the downlink control channel;

mapping a linear combination of the first, second, and third offsets to an index identifying a first allocated PUCCH resource; and

receiving a PUCCH on the first allocated PUCCH resource.

20. The method of claim 19 , wherein a plurality of physical downlink shared channels (PDSCHs) are to be transmitted to the UE, respective ones of the PDSCHs being transmitted in respective different subframes, and wherein the mapping of the linear combination comprises adding a first subframe offset corresponding to a first subframe in which a first one of the PDSCHs is to be transmitted.

21. The method of claim 19 , further comprising:

determining a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

receiving a PUCCH on one of the first or the second allocated PUCCH resources using a first antenna port.

22. The method of claim 19 , further comprising:

determining a second allocated PUCCH resource, the second allocated PUCCH resource having a value equal to the first allocated PUCCH resource plus a constant; and

receiving the PUCCH on the first allocated PUCCH resource using a first antenna port and on the second allocated PUCCH resource using a second antenna port, the PUCCH being received simultaneously on the first and second antenna ports.

23. The method of claim 19 , wherein the downlink control channel is in a downlink control information (DCI) format.

24. The method of claim 19 , further comprising:

determining a fourth offset based on a transmission mode of the downlink control channel, wherein the transmission mode is one of localized transmission or distributed transmission; and

mapping a linear combination of the first, second, third, and fourth offsets to the index identifying the first allocated PUCCH resource.

25. The method of claim 19 , wherein the first value is a number of enhanced control channel elements (eCCEs).

26. The method of claim 25 , wherein determining the second offset comprises determining the largest integer that is smaller than or equal to the position of the transmitted downlink control channel normalized by the first value.

27. The method of claim 19 , wherein the first value is a length of enhanced physical downlink control channel (ePDCCH).