METHOD AND APPARATUS FOR SCHEDULING AN ACKNOWLEDGEMENT TRANSMISSION

Abstract

A communication system distributes, in the time domain, acknowledgment transmissions by a group of access terminals sharing a same time domain resource. A position of one or more access terminals in the group of access terminals is determined and each of the one or more access terminals then sends an acknowledgment transmission, such as an acknowledgment or negative acknowledgement, in a time slot that is N time slots after the shared time domain resource, where N is a function of the position of the access terminal in the group of access terminals.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless communication system in accordance an embodiment of the present invention.

FIG. 2 is a block diagram of an access terminal in accordance with various embodiments of the present invention.

FIG. 3 is a logic flow diagram illustrating an acknowledgment transmission scheme executed by the communication system of FIG. 1 in accordance with various embodiments of the present invention.

FIG. 4 is an exemplary timing diagram depicting a utilization of time domain resources by the communication system of FIG. 1 in accordance with an embodiment of the present invention.

FIG. 5 is an exemplary timing diagram depicting a utilization of time domain resources by the communication system of FIG. 1 in accordance with another embodiment of the present invention.

FIG. 6 is an exemplary timing diagram depicting a utilization of time domain resources by the communication system of FIG. 1 in accordance with another embodiment of the present invention.

Claims

1. A method for transmitting an acknowledgement comprising: determining a position of an access terminal in a group of access terminals sharing a same time domain resource; andsending an acknowledgment or negative acknowledgement indication in a time slot that is N time slots after the shared time domain resource, where N is a function of the position of the access terminal in the group of access terminals.

2. The method according to claim 1, wherein determining a position comprises determining position of the access terminal in the group of access terminals based on an index value assigned to the access terminal, wherein the index value corresponds to a portion of the shared time domain resource.

3. The method according to claim 2, wherein the shared time domain resource comprises a set of Walsh codes and the index value corresponds to a particular Walsh Code.

4. The method according to claim 2, wherein the shared time domain resource comprises a set of subcarriers and the index value corresponds to a particular subset of the set of subcarriers.

5. The method according to claim 2, further comprising receiving the index value assigned to the access terminal via a control channel.

6. The method according to claim 5, further comprising receiving a unique identifier associated with the access terminal via the control channel.

7. The method according to claim 1, wherein determining a position comprises determining a position of the access terminal in the group of access terminals based on a position of the access terminal in a list of access terminals.

8. The method according to 7, wherein the list of access terminals is a list of unique identifiers.

9. The method according to claim 7, wherein the list of access terminals is received in a header of a multiple user packet.

10. The method according to claim 7, further comprising receiving the list of access terminals via a control channel.

11. The method according to claim 1, wherein determining a position comprises: receiving an indication of a location within a bitmap;receiving a bitmap, where one of the binary values in each bitmap location represents that a resource has been assigned for an access terminal; anddetermining a position as the summation of a number of access terminals with assigned resources and bitmap locations less than or equal to the location within the bitmap.

12. The method according to claim 1, wherein the function is a modulus function, where one argument of the modulus function is a position of the access terminal, the other argument of the modulus function is a total number of time slots available for sending acknowledgment information, and the output of the modulus function is N.

13. The method according to claim 1, wherein the function is a lookup table, where an input of the lookup table is a position of the access terminal and an output of the lookup table is N.

14. The method according to claim 1, further comprising receiving a message comprising an indication of the function.

15. A method for receiving acknowledgement transmissions, the method comprising: determining when to expect an acknowledgement or negative acknowledgment transmission based on one or more of a position of an access terminal in a group of access terminals sharing a same time domain resource and a function used at the access terminal; anddecoding the acknowledgment or negative acknowledgement transmission from the access terminal only in an expected time slot.

16. A method for distributing acknowledgment transmissions, the method comprising: determining a processing capability of the access terminal;assigning the access terminal a position in a group of access terminals such that the access terminal has enough processing time to decode a transmission before transmitting an acknowledgment or a negative acknowledgement; andsending the access terminal an indication of the access terminal's position in the group of access terminals.

17. An access terminal comprising a processor configured to determine a position of the access terminal in a group of access terminals sharing a same time domain resource and send an acknowledgment or negative acknowledgement indication in a time slot that is N time slots after the shared time domain resource, where N is a function of the position of the access terminal in the group of access terminals.

18. The access terminal according to claim 17, wherein the processor determines a position of the access terminal in the group of access terminals based on an index value assigned to the access terminal, wherein the index value corresponds to one portion of the shared time domain resource.

19. The access terminal according to claim 18, wherein the shared time domain resource comprises a set of Walsh codes and the index value corresponds to a particular Walsh Code.

20. The access terminal according to claim 18, wherein the shared time domain resource comprises a set of subcarriers and the index value corresponds to a particular subset of subcarriers.

21. The access terminal according to claim 18, wherein the access terminal receives the assigned index value via a control channel.

22. The access terminal according to claim 21, wherein the access terminal further receives a unique identifier associated with the wireless receiver.

23. The access terminal according to claim 17, wherein the wherein the processor determines a position of the access terminal in the group of access terminals based on a position of the access terminal in a list of access terminals.

24. The access terminal according to 23, wherein the list of access terminals is a list of unique identifiers.

25. The access terminal according to claim 23, wherein the list of access terminals is received in a header of a multiple user packet.

26. The access terminal according to claim 23, wherein the list of access terminals is received via a control channel.

27. The access terminal according to claim 17, wherein the processor determines a position by receiving an indication of a location within a bitmap, receiving a bitmap, where one of the binary values in each bitmap location represents that a resource has been assigned for an access terminal, and determining a position as the summation of a number of access terminals with assigned resources and bitmap locations less than or equal to the location within the bitmap.

28. The access terminal according to claim 17, wherein the function is a modulus function, where one argument of the modulus function is a position of the access terminal, the other argument of the modulus function is a total number of time slots available for sending acknowledgment information, and the output of the modulus function is N.

29. The access terminal according to claim 17, wherein the function is a lookup table, where an input of the lookup table is a position of the access terminal and an output of the lookup table is N.

30. The access terminal according to claim 17, wherein the access terminal receives a message comprising an indication of the function.

31. An access network element that determines when to expect an acknowledgement or negative acknowledgment transmission based on one or more of a position of an access terminal in a group of access terminals sharing a same time domain resource and a function used at the access terminal and decodes the acknowledgment or negative acknowledgement transmission from the access terminal only in an expected time slot.

32. A network controller that distributes acknowledgment transmissions, wherein the network controller determines a processing capability of the access terminal, assigns the access terminal a position in a group of access terminals such that the access terminal has enough processing time to decode a transmission before transmitting an acknowledgment or a negative acknowledgement, and sends the access terminal an indication of the access terminal's position in the group of access terminals.