Overhead reduction for transmission of acknowledgment signals

1. A method of operating a User Equipment (UE) to transmit a Hybrid Automatic Repeat reQuest Acknowledgment (HARQ-ACK) signal in a Physical Uplink Control CHannel (PUCCH), the method comprising:

detecting each Physical Downlink Control CHannel (PDCCH) of one or more PDCCHs of a first type transmitted from a base station over respective one or more Transmission Time Interval (TTIs) within a total number of M TTIs and within a set j of Physical Resource Block (PRB) pairs, wherein a PRB pair includes a number of sub-carriers over a TTI, and wherein each PDCCH is detected over a respective number of Control Channel Elements (CCEs) and conveys a Downlink Control Information (DCI) format that includes a HARQ-ACK Resource Offset (HRO) information field having Q binary elements;

determining a PUCCH resource n PUCCH in response to a PDCCH detection in TTI m, 0≦m≦M−1, as

n

PUCCH

=

n

CCE

,

m

,

j

+

f

⁡

(

H

⁢

⁢

R

⁢

⁢

O

)

+

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

+

N

PUCCH

,

j

,

wherein n CCE,m,j is an index for a first CCE of the PDCCH in TTI m, ƒ(HRO) is a mapping function for the HRO information field having an even number of integer outputs, N CCE,i,j is a total number of CCEs in TTI i, and N PUCCH,j is informed to the UE from the base station by higher layer signaling, and wherein for m=0 all ƒ(HRO) values are small integers and for m>0 a first even number of ƒ(HRO) values are same as for m=0 and do not depend on a value of m and a remaining second even number of ƒ(HRO) values are larger negative integers that depend on the value of m and include a term that is a sum of one or more −N CCE,i,j values where 0≦i≦m−1; and

transmitting the HARQ-ACK signal in the determined PUCCH resource.

2. The method of claim 1 , wherein Q=2, the first even number of ƒ(HRO) values is two, and the remaining second even number of ƒ(HRO) values is two with a first value including a term

-

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

.

3. The method of claim 2 , wherein a second value of the remaining second even number of ƒ(HRO) values includes a term −N CCE,m−1,j .

4. The method of claim 1 , wherein for m=0 the ƒ(HRO) values are {−2, −1, 0, 2}.

5. The method of claim 1 , wherein a first value of Q is associated with a first value of M and a second value of Q is associated with a second value of M, wherein the first value of Q is smaller than the second value of Q and the first value of M is smaller than the second value of M.

6. The method of claim 1 , wherein the DCI format includes a Downlink Assignment Index (DAI) field, the DAI field at TTI m indicating a total number of DCI formats transmitted to the UE from TTI 0 until TTI m and wherein, for at least some values of m, at least one binary element from the DAI field is used as a binary element of the HRO field.

7. The method of claim 1 , wherein the UE detects a PDCCH of a second type in TTI m 1 , 0≦m 1 ≦m−1 and m>0.

8. The method of claim 1 , wherein the PDCCH is transmitted within one PRB pair and n CCE,m,j is replaced by:

n CCE,m,j L =└n CCE,m,j /N CCE — PRB,m,j ┘+( n CCE,m,j mod N CCE — PRB,m,j )· N PRB,j

where N CCE — PRB,m,j is a number of CCEs within a PRB pair, N PRB,j is a total number of PRB pairs in the set j of PRB pairs, and └ ┘ is a floor function that rounds a number to a next integer that is less than or equal to the number.

9. A method of operating a base station to receive a Hybrid Automatic Repeat reQuest Acknowledgment (HARQ-ACK) signal transmitted from a User Equipment (UE) in a Physical Uplink Control CHannel (PUCCH), the method comprising:

transmitting one or more Physical Downlink Control CHannels (PDCCHs) of a first type over respective one or more Transmission Time Interval (TTIs) within a total number of M TTIs and within a set j of Physical Resource Block (PRB) pairs, wherein a PRB pair includes a number of sub-carriers over a TTI, and wherein each PDCCH is transmitted over a respective number of Control Channel Elements (CCEs) and conveys a Downlink Control Information (DCI) format that includes a HARQ-ACK Resource Offset (HRO) information field having Q binary elements;

determining a PUCCH resource n PUCCH in response to a PDCCH transmission in TTI m, 0≦m≦M−1, as

n

PUCCH

=

n

CCE

,

m

,

j

+

f

⁡

(

H

⁢

⁢

R

⁢

⁢

O

)

+

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

+

N

PUCCH

,

j

,

wherein n CCE,m,j is an index for a first CCE of the PDCCH in TTI m, ƒ(HRO) is a mapping function for the HRO information field having an even number of integer outputs, N CCE,i,j is a total number of CCEs in TTI i, and N PUCCH,j is informed to the UE from the base station by higher layer signaling, and wherein for m=0 all ƒ(HRO) values are small integers and for m>0 a first even number of ƒ(HRO) values are same as for m=0 and do not depend on a value of m and a remaining second even number of ƒ(HRO) values are larger negative integers that depend on the value of m and include a term that is a sum of one or more −N CCE,i,j values where 0≦i≦m−1; and

receiving the HARQ-ACK signal in the determined PUCCH resource.

10. The method of claim 9 , wherein Q=2, the first even number of ƒ(HRO) values is two, and the remaining second even number of ƒ(HRO) values is two with a first value including the term

-

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

.

11. The method of claim 10 , wherein a second value of the remaining second even number of ƒ(HRO) values includes a term −N CCE,m−1,j .

12. The method of claim 9 , wherein for m=0 the ƒ(HRO) values are {−2, −1, 0, 2}.

13. The method of claim 9 , wherein a first value of Q is associated with a first value of M and a second value of Q is associated with a second value of M, wherein the first value of Q is smaller than the second value of Q and the first value of M is smaller than the second value of M.

14. The method of claim 9 , wherein the DCI format includes a Downlink Assignment Index (DAI) field, the DAI field at TTI m indicating a total number of DCI formats transmitted to the UE from TTI 0 until TTI m and wherein, at least for some values of m, at least one binary element from the DAI field is used as a binary element of the HRO field.

15. The method of claim 9 , wherein the base station transmits to the UE a PDCCH of a second type in TTI m 1 , 0 m 1 ≦m−1 and m>0.

16. The method of claim 9 , wherein the PDCCH is transmitted within one PRB pair and n CCE,m,j is replaced by:

n CCE,m,j L =└n CCE,m,j /N CCE — PRB,m,j ┘+( n CCE,m,j mod N CCE — PRB,m,j )· N PRB,j

where N CCE — PRB,m,j is a number of CCEs within a PRB pair, N PRB,j is a total number of PRB pairs in the set j of PRB pairs, and └ ┘ is a floor function that rounds a number to a next integer that is less than or equal to the number.

17. An apparatus in a User Equipment (UE) capable of transmitting a Hybrid Automatic Repeat reQuest Acknowledgment (HARQ-ACK) signal in a Physical Uplink Control CHannel (PUCCH), the apparatus comprising:

a detector configured to detect one or more Physical Downlink Control CHannels (PDCCHs) of a first type transmitted from a base station over respective one or more Transmission Time Interval (TTIs) within a total number of M TTIs and within a set j of Physical Resource Block (PRB) pairs, wherein a PRB pair includes a number of sub-carriers over a TTI, and wherein each PDCCH is detected over a respective number of Control Channel Elements (CCEs) and conveys a Downlink Control Information (DCI) format that includes a HARQ-ACK Resource Offset (HRO) information field having Q binary elements;

a computing unit configured to determine a PUCCH resource n PUCCH in response to a PDCCH detection in TTI m, 0≦m≦M−1, as

n

PUCCH

=

n

CCE

,

m

,

j

+

f

⁡

(

H

⁢

⁢

R

⁢

⁢

O

)

+

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

+

N

PUCCH

,

j

,

wherein n CCE,m,j is an index for a first CCE of the PDCCH in TTI m, ƒ(HRO) is a mapping function for the HRO information field having an even number of integer outputs, N CCE,i,j is a total number of CCEs in TTI i, and N PUCCH,j is informed to the apparatus from the base station by higher layer signaling, and wherein for m=0 all ƒ(HRO) values are small integers and for m>0 a first even number of ƒ(HRO) values are same as for m=0 and do not depend on a value of m and a remaining second even number of ƒ(HRO) values are larger negative integers that depend on the value of m and include a term that is a sum of one or more −N CCE,i,j values where 0≦i≦m−1; and

a transmitter configured to transmit the HARQ-ACK signal in the determined PUCCH resource.

18. The apparatus of claim 17 , wherein Q=2, the first even number of ƒ(HRO) values is two, and the remaining second even number of ƒ(HRO) values is two with a first value including a term

-

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

.

19. The apparatus of claim 18 , wherein a second value of the remaining second even number of ƒ(HRO) values includes a term −N CCE,m−1,j .

20. The apparatus of claim 17 , wherein for m=0 the ƒ(HRO) values are {−2, −1, 0, 2}.

21. The apparatus of claim 17 , wherein a first value of Q is associated with a first value of M and a second value of Q is associated with a second value of M, wherein the first value of Q is smaller than the second value of Q and the first value of M is smaller than the second value of M.

22. The apparatus of claim 17 , wherein the DCI format includes a Downlink Assignment Index (DAI) field, the DAI field at TTI m indicating a total number of DCI formats transmitted to the UE from TTI 0 until TTI m and wherein, at least for some values of m, at least one binary element from the DAI field is used as a binary element of the HRO field.

23. The apparatus of claim 17 , wherein the apparatus detects a PDCCH of a second type in TTI m 1 , 0≦m 1 ≦m−1 and m>0.

24. The apparatus of claim 17 , wherein the PDCCH is transmitted within one PRB pair and n CCE,m,j is replaced by:

n CCE,m,j L =└n CCE,m,j /N CCE — PRB,m,j ┘+( n CCE,m,j mod N CCE — PRB,m,j )· N PRB,j

where N CCE — PRB,m,j is a number of CCEs within a PRB pair, N PRB,j is a total number of PRB pairs in the set j of PRB pairs, and └ ┘ is a floor function that rounds a number to a next integer that is less than or equal to the number.

25. An apparatus in a base station capable of receiving a Hybrid Automatic Repeat reQuest Acknowledgment (HARQ-ACK) signal transmitted from a User Equipment (UE) in a Physical Uplink Control CHannel (PUCCH), the apparatus comprising:

a transmitter configured to transmit one or more Physical Downlink Control CHannels (PDCCHs) of a first type over respective one or more Transmission Time Interval (TTIs) within a total number of M TTIs and within a set j of Physical Resource Block (PRB) pairs, wherein a PRB pair includes a number of sub-carriers over a TTI, and wherein each PDCCH is transmitted over a respective number of Control Channel Elements (CCEs) and conveys a Downlink Control Information (DCI) format that includes a HARQ-ACK Resource Offset (HRO) information field having Q binary elements;

a computing unit configured to determine a PUCCH resource n PUCCH in response to a PDCCH transmission in TTI m, 0≦m≦M−1, as

n

PUCCH

=

n

CCE

,

m

,

j

+

f

⁡

(

H

⁢

⁢

R

⁢

⁢

O

)

+

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

+

N

PUCCH

,

j

,

wherein n CCE,m,j is an index for a first CCE of the PDCCH in TTI m, ƒ(HRO) is a mapping function for the HRO information field having an even number of integer outputs, N CCE,i,j is a total number of CCEs in TTI i, and N PUCCH,j is informed to the UE from the base station by higher layer signaling, and wherein for m=0 all ƒ(HRO) values are small integers and for m>0 a first even number of ƒ(HRO) values are same as for m=0 and do not depend on a value of m and a remaining second even number of ƒ(HRO) values are larger negative integers that depend on the value of m and include a term that is a sum of one or more −N CCE,i,j values where 0≦i≦m−1; and

a receiver configured to receive the HARQ-ACK signal in the determined PUCCH resource.

26. The apparatus of claim 25 , wherein Q=2, the first even number of ƒ(HRO) values is two, and the remaining second even number of ƒ(HRO) values is two with a first value including the term

-

∑

i

=

0

m

-

1

⁢

N

CCE

,

i

,

j

.

27. The apparatus of claim 26 , wherein a second value of the remaining second even number of ƒ(HRO) values includes a term −N CCE,m−1,j .

28. The apparatus of claim 25 , wherein for m=0 the ƒ(HRO) values are {−2, −1, 0, 2}.

29. The apparatus of claim 25 , wherein a first value of Q is associated with a first value of M and a second value of Q is associated with a second value of M, wherein the first value of Q is smaller than the second value of Q and the first value of M is smaller than the second value of M.

30. The apparatus of claim 25 , wherein the DCI format includes a Downlink Assignment Index (DAI) field, the DAI field at TTI m indicating a total number of DCI formats transmitted to the UE from TTI 0 until TTI m and wherein, at least for some values of m, at least one binary element from the DAI field is used as a binary element of the HRO field.

31. The apparatus of claim 25 , wherein the apparatus transmits to the UE a PDCCH of a second type in TTI m 1 , 0≦m 1 ≦m−1 and m>0.

32. The apparatus of claim 25 , wherein the PDCCH is transmitted within one PRB pair and n CCE,m,j is replaced by:

n CCE,m,j L =└n CCE,m,j /N CCE — PRB,m,j ┘+( n CCE,m,j mod N CCE — PRB,m,j )· N PRB,j

where N CCE — PRB,m,j is a number of CCEs within a PRB pair, N PRB,j is a total number of PRB pairs in the set j of PRB pairs, and └ ┘ is a floor function that rounds a number to a next integer that is less than or equal to the number.