Assignment of ACK resource in a wireless communication system

1. A method for wireless communication, comprising:

obtaining, by a wireless communication device, a first parameter indicative of radio resources allocated to a user equipment (UE) for data transmission;

obtaining, by the wireless communication device, a second parameter indicative of another resource assigned to the UE for data transmission, wherein at least one of the first and second parameters is restricted, and each restricted parameter is limited to a set of allowed values among all available values for the parameter;

determining, by the wireless communication device, a third parameter indicative of a minimum amount of radio resources to allocate to the UE; and

determining, by the wireless communication device, acknowledgement (ACK) resource assigned to the UE for data transmission based on the first, second, and third parameters,

wherein the determining the third parameter comprises

obtaining a fourth parameter indicative of amount of available ACK resources,

obtaining a fifth parameter indicative of amount of available radio resources, and

determining the third parameter based on the fourth and fifth parameters.

2. The method of claim 1 , wherein the first parameter comprises a lowest index of at least one physical resource block (PRB) allocated to the UE for data transmission.

3. The method of claim 1 , wherein the second parameter comprises a cyclic shift of a reference signal sequence assigned to the UE for data transmission.

4. The method of claim 3 , wherein the set of allowed values for the second parameter comprises values within a range of 0 to M−1 for M-way spatial division multiple access (SDMA), where M is one or greater.

5. The method of claim 4 , wherein M different cyclic shifts of the reference signal sequence are associated with M allowed values for the second parameter, and wherein distance between the M cyclic shifts is dependent on M.

6. The method of claim 1 , wherein sequential values of the first parameter are mapped to sequential indices of available ACK resources, and wherein each allowed value of the second parameter is associated with a different starting ACK resource index.

7. The method of claim 1 , wherein for a first allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially increasing indices of available ACK resources, starting with a smallest ACK resource index, and wherein for a second allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially decreasing indices of the available ACK resources, starting with a largest ACK resource index.

8. The method of claim 1 , wherein the third parameter is determined based further on M for M-way spatial division multiple access (SDMA), where M is one or greater.

9. The method of claim 1 , wherein the determining the third parameter comprises determining the third parameter based on number of uplink carriers mapped to a downlink carrier.

10. The method of claim 1 , wherein the determining the ACK resource comprises

determining an intermediate index based on the first, second and third parameters, and

mapping the intermediate index to an index of the ACK resource assigned to the UE based on a predetermined mapping.

11. The method of claim 10 , wherein the intermediate index is determined in accordance with

I PRB adjusted =└I PRB — RA lowest — index /l adjacent — 1 ┘+I offset ,

where I PRB — RA lowest — index is the first parameter,

I offset is an offset determined based on the second parameter,

l adjacent — 1 is the third parameter for non-SDMA, and

I PRB adjusted is the intermediate index.

12. The method of claim 1 , wherein the third parameter is selected to avoid collisions in mapping the first and second parameters to available ACK resources.

13. The method of claim 1 , wherein the set of allowed values for the second parameter is selected to avoid collisions in mapping the first and second parameters to available ACK resources.

14. The method of claim 1 , further comprising:

sending data on the radio resources allocated to the UE; and

receiving ACK information for the data on the ACK resource assigned to the UE.

15. The method of claim 1 , further comprising:

receiving data on the radio resources allocated to the UE; and

sending ACK information for the data on the ACK resource assigned to the UE.

16. The method of claim 1 , wherein the ACK resource comprises an index of an orthogonal sequence for a physical HARQ indicator channel (PHICH) and an index of a PHICH group.

17. An apparatus for wireless communication, comprising:

means for obtaining a first parameter indicative of radio resources allocated to a user equipment (UE) for data transmission;

means for obtaining a second parameter indicative of another resource assigned to the UE for data transmission, wherein at least one of the first and second parameters is restricted, and each restricted parameter is limited to a set of allowed values among all available values for the parameter;

means for determining a third parameter indicative of a minimum amount of radio resources to allocate to the UE; and

means for determining acknowledgement (ACK) resource assigned to the UE for data transmission based on the first, second, and third parameter,

wherein the means for determining the third parameter comprises

means for obtaining a fourth parameter indicative of amount of available ACK resources,

means for obtaining a fifth parameter indicative of amount of available radio resources, and

means for determining the third parameter based on the fourth and fifth parameters.

18. The apparatus of claim 17 , wherein the first parameter comprises a lowest index of at least one physical resource block (PRB) allocated to the UE for data transmission.

19. The apparatus of claim 17 , wherein the second parameter comprises a cyclic shift of a reference signal sequence assigned to the UE for data transmission, and wherein the set of allowed values for the second parameter comprises values within a range of 0 to M−1 for M-way spatial division multiple access (SDMA), where M is one or greater.

20. The apparatus of claim 17 , wherein sequential values of the first parameter are mapped to sequential indices of available ACK resources, and wherein each allowed value of the second parameter is associated with a different starting ACK resource index.

21. The apparatus of claim 17 , wherein for a first allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially increasing indices of available ACK resources, starting with a smallest ACK resource index, and wherein for a second allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially decreasing indices of the available ACK resources, starting with a largest ACK resource index.

22. An apparatus for wireless communication, comprising:

at least one processor configured to obtain a first parameter indicative of radio resources allocated to a user equipment (UE) for data transmission, to obtain a second parameter indicative of another resource assigned to the UE for data transmission, wherein at least one of the first and second parameters is restricted, and each restricted parameter is limited to a set of allowed values among all available values for the parameter, to determine a third parameter indicative of a minimum amount of radio resources to allocate to the UE, and to determine acknowledgement (ACK) resource assigned to the UE for data transmission based on the first, second, and third parameters,

wherein the at least one processor is configured to obtain a fourth parameter indicative of amount of available ACK resources, to obtain a fifth parameter indicative of amount of available radio resources, and to determine the third parameter based on the fourth and fifth parameters.

23. The apparatus of claim 22 , wherein the first parameter comprises a lowest index of at least one physical resource block (PRB) allocated to the UE for data transmission.

24. The apparatus of claim 22 , wherein the second parameter comprises a cyclic shift of a reference signal sequence assigned to the UE for data transmission, and wherein the set of allowed values for the second parameter comprises values within a range of 0 to M−1 for M-way spatial division multiple access (SDMA), where M is one or greater.

25. The apparatus of claim 22 , wherein sequential values of the first parameter are mapped to sequential indices of available ACK resources, and wherein each allowed value of the second parameter is associated with a different starting ACK resource index.

26. The apparatus of claim 22 , wherein for a first allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially increasing indices of available ACK resources, starting with a smallest ACK resource index, and wherein for a second allowed value of the second parameter, sequentially increasing values of the first parameter are mapped to sequentially decreasing indices of the available ACK resources, starting with a largest ACK resource index.

27. A computer program product, comprising:

a non-transitory computer-readable medium comprising:

code for causing at least one computer to obtain a first parameter indicative of radio resources allocated to a user equipment (UE) for data transmission,

code for causing the at least one computer to obtain a second parameter indicative of another resource assigned to the UE for data transmission, wherein at least one of the first and second parameters is restricted, and each restricted parameter is limited to a set of allowed values among all available values for the parameter,

code for causing the at least one computer to determine a third parameter indicative of a minimum amount of radio resources to allocate to the UE, and

code for causing the at least one computer to determine acknowledgement (ACK) resource assigned to the UE for data transmission based on the first, second, and third parameters,

wherein the code for causing the at least one computer to determine the third parameter comprises

code for causing the at least one computer to obtain a fourth parameter indicative of amount of available ACK resources,

code for causing the at least one computer to obtain a fifth parameter indicative of amount of available radio resources, and

code for causing the at least one computer to determine the third parameter based on the fourth and fifth parameters.

28. A method for wireless communication performed by a device, comprising:

obtaining a first parameter indicative of radio resources allocated to a user equipment (UE) for data transmission;

obtaining a second parameter indicative of another resource assigned to the UE for data transmission, wherein at least one of the first and second parameters is restricted, and each restricted parameter is limited to a set of allowed values among all available values for the parameter; and

determining acknowledgement (ACK) resource assigned to the UE for data transmission based on the first and second, and a third parameters,

wherein the determining the ACK resource comprises:

determining an intermediate index based on the first and second parameters, and

mapping the intermediate index to an index of the ACK resource assigned to the UE based on a predetermined mapping.

29. The method of claim 28 , wherein the intermediate index is determined in accordance with

I

PRB

adjusted

=

{

I

PRB_RA

lowest_index

+

I

offset

for

⁢

⁢

a

⁢

⁢

first

⁢

⁢

set

⁢

⁢

of

n

DMRS

⁢

⁢

values

I

max

-

I

PRB_RA

lowest_index

-

I

offset

for

⁢

⁢

a

⁢

⁢

second

⁢

⁢

set

⁢

⁢

of

n

DMRS

⁢

⁢

values

where I PRB — RA lowest — index is the first parameter,

n DMRS is the second parameter,

I offset is an offset determined based on the second parameter,

I max is a largest ACK resource index, and

I PRB adjusted is the intermediate index.