Granted Patent B2

US 8,825,100 · App. 12/336,901 · Granted Sep 2, 2014

Abstract

Claims (67)

1. A method of operating a base station in a cellular communications network to provide a power boost for a communications link between the base station and a user device over a communications link channel having a full channel bandwidth including a plurality of sub-carrier frequencies, comprising:

receiving a wideband channel quality index from the user device;

receiving a plurality of sub-band channel quality indices from the user device;

determining whether a power boost is needed for a communications link between the base station and the user device based on the received wideband channel quality index;

if a power boost is needed for the communications link between the base station and the user device, using a subset of the plurality of sub-carrier frequencies of the communications link channel as a reduced bandwidth channel for the communications link to the user device such that signal power is concentrated on the subset of the plurality of sub-carrier frequencies in the reduced bandwidth channel rather than distributed across the full channel bandwidth, thereby providing a power boost for the communications link to the user device, wherein the subset of the plurality of sub-carrier frequencies are determined based at least in part on the received the plurality of sub-band channel quality indices; and

coordinating the subset of the plurality of sub-carrier frequencies of the communications link channel with at least one other base station, wherein the other base station uses a different subset of the plurality of sub-carrier frequencies, wherein the subset of the plurality of sub-carrier frequencies are coordinated based on an indication of a number of resource blocks, each resource block containing twelve sub-carrier frequencies.

2. The method of claim 1 wherein using the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device comprises allocating one or more sub-carrier frequencies from the subset of the plurality of sub-carrier frequencies in the reduced bandwidth channel for the communications link to the user device during a transmit time interval when only the reduced bandwidth channel is utilized.

3. The method of claim 1 wherein using the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device comprises:

determining a reduced channel bandwidth needed for a desired power boost for the communications link to the user device; and

identifying the subset of the plurality of sub-carrier frequencies for the reduced bandwidth channel such that a bandwidth of the reduced bandwidth channel is less than or equal to the reduced channel bandwidth needed for the desired power boost.

4. The method of claim 1 wherein the base station serves a cell of the cellular communications network including a plurality of sectors, each sector of the plurality of sectors is assigned a different set of sub-carrier frequencies from the plurality of sub-carrier frequencies of the communications link channel, and the subset of the plurality of sub-carrier frequencies used as the reduced bandwidth channel is at least a subset of the set of sub-carrier frequencies assigned to a sector of the plurality of sectors currently serving the user device.

5. The method of claim 4 wherein using the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device comprises:

identifying a number of sub-carrier frequencies from the at least a subset of the set of

sub-carrier frequencies assigned to the sector currently serving the user device that have a least amount of out-of-cell interference; and

allocating the number of sub-carrier frequencies during a transmit time interval for the communications link to the user device.

6. The method of claim 1 wherein a power boost per sub-carrier frequency for the communications link to the user device is related to a ratio of the full channel bandwidth to a reduced channel bandwidth of the reduced bandwidth channel.

7. The method of claim 1 wherein determining whether a power boost is needed for the communications link comprises:

obtaining a communications link signal-to-interference-plus-noise ratio (SINR) for the user device; and

determining that a power boost is needed if the communications link SINR is less than a predetermined threshold.

8. The method of claim 7 wherein the predetermined threshold is a minimum SINR needed to maintain a communications link with the base station plus a margin.

9. The method of claim 1 further comprising using the communications link channel having the full channel bandwidth for the communications link to the user device if a power boost is not needed for the communications link between the base station and the user device.

10. The method of claim 9 wherein using the communications link channel having the full channel bandwidth for the communications link to the user device comprises allocating one or more sub-carrier frequencies from the plurality of sub-carrier frequencies in the full channel bandwidth of the communications link channel for the communications link to the user device during a transmit time interval in which the full channel bandwidth of the communications link channel is utilized.

11. The method of claim 10 wherein using the communications link channel having the full channel bandwidth for the communications link to the user device further comprises using −X decibel (dB) power backoff for the communications link to the user device.

12. The method of claim 1 wherein the communications link channel is a downlink channel and the communications link is a downlink.

13. The method of claim 12 wherein the downlink channel is an orthogonal frequency division multiple access (OFDMA) channel.

14. The method of claim 1 wherein the communications link channel is an uplink channel and the communications link is an uplink.

15. The method of claim 14 wherein the uplink channel is a single-carrier frequency division multiple access (SC-FDMA) channel.

16. A base station in a cellular communications network, comprising:

one or more sector transceivers providing communications links to user devices located within a cell of the cellular communications network served by the base station via a communications link channel having a full channel bandwidth including a plurality of sub-carrier frequencies; and

a control system associated with the one or more sector transceivers and adapted to:

receive a wideband channel quality index from the user device;

receive a plurality of sub-band channel quality indices from the user device;

determine whether a power boost is needed for a communications link between the base station and a user device over the communications link channel based on the received wideband channel quality index;

if a power boost is needed for the communications link between the base station and the user device, use a subset of the plurality of sub-carrier frequencies of the communications link channel as a reduced bandwidth channel for the communications link to the user device such that signal power is concentrated on the subset of the plurality of sub-carrier frequencies in the reduced bandwidth channel rather than distributed across the full channel bandwidth, thereby providing a power boost for the communications link to the user device, wherein the subset of the plurality of sub-carrier frequencies are determined based at least in part on the received the plurality of sub-band channel quality indices; and

coordinate the subset of the plurality of sub-carrier frequencies of the communications link channel with at least one other base station, wherein the other base station uses a different subset of the plurality of sub-carrier frequencies, wherein the subset of the plurality of sub-carrier frequencies are coordinated based on an indication of a number of resource blocks, each resource block containing twelve sub-carrier frequencies.

17. The base station of claim 16 wherein the communications link channel is a downlink channel and the communications link is a downlink.

18. The base station of claim 16 wherein the communications link channel is an uplink channel and the communications link is an uplink.

19. The method of claim 1 , wherein the base station serves a cell of the cellular communications network including a plurality of sectors, each sector of the plurality of sectors is assigned a different set of sub-carrier frequencies for use with power boost.

20. The method of claim 1 , further comprising transmitting a message to the user device, the message configuring the user device to report a plurality of sub-band channel quality indications.

21. The method of claim 1 , wherein determining whether a power boost is needed is at least partially based on the received the plurality of sub-band channel quality indices.

22. The method of claim 1 , further comprising allocating the selected sub-carrier frequencies to the user device during one transmit time interval by allocating one or more resource blocks, each resource block corresponding to twelve sub-carrier frequencies.

23. The method of claim 1 , wherein at least one of the at least one other base station transmits a signal to a second user device using at least a portion of the subset of the plurality of sub-carrier frequencies during one transmit time interval.

24. The method of claim 1 , further comprising allocating the resource blocks to the user device.

25. The base station of claim 16 , wherein to use the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device the control system is adapted to allocate one or more sub-carrier frequencies from the subset of the plurality of sub-carrier frequencies in the reduced bandwidth channel for the communications link to the user device during a transmit time interval when only the reduced bandwidth channel is utilized.

26. The base station of claim 16 , wherein to use the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device the control system is adapted to:

determine a reduced channel bandwidth needed for a desired power boost for the communications link to the user device; and

identify the subset of the plurality of sub-carrier frequencies for the reduced bandwidth channel such that a bandwidth of the reduced bandwidth channel is less than or equal to the reduced channel bandwidth needed for the desired power boost.

27. The base station of claim 16 , wherein the cell of the cellular communications network served by the base station comprises a plurality of sectors, each sector of the plurality of sectors is assigned a different set of sub-carrier frequencies from the plurality of sub-carrier frequencies of the communications link channel, and the subset of the plurality of sub-carrier frequencies used as the reduced bandwidth channel is at least a subset of the set of sub-carrier frequencies assigned to a sector of the plurality of sectors currently serving the user device.

28. The base station of claim 27 , wherein to use the subset of the plurality of sub-carrier frequencies of the communications link channel as the reduced bandwidth channel for the communications link to the user device the control system is adapted to:

identify a number of sub-carrier frequencies from the at least a subset of the set of sub-carrier frequencies assigned to the sector currently serving the user device that have a least amount of out-of-cell interference; and

allocate the number of sub-carrier frequencies during a transmit time interval for the communications link to the user device.

29. The base station of claim 16 , wherein a power boost per sub-carrier frequency for the communications link to the user device is related to a ratio of the full channel bandwidth to a reduced channel bandwidth of the reduced bandwidth channel.

30. The base station of claim 16 , wherein to determine whether a power boost is needed for the communications link the control system is adapted to:

obtain a communications link signal-to-interference-plus-noise ratio (SINR) for the user device; and

determine that a power boost is needed if the communications link SINR is less than a predetermined threshold.

31. The base station of claim 30 , wherein the predetermined threshold is a minimum SINR needed to maintain a communications link with the base station plus a margin.

32. The base station of claim 16 , the control system adapted to use the communications link channel having the full channel bandwidth for the communications link to the user device if a power boost is not needed for the communications link between the base station and the user device.

33. The base station of claim 32 , wherein to use the communications link channel having the full channel bandwidth for the communications link to the user device the control system is adapted to allocate one or more sub-carrier frequencies from the plurality of sub-carrier frequencies in the full channel bandwidth of the communications link channel for the communications link to the user device during a transmit time interval in which the full channel bandwidth of the communications link channel is utilized.

34. The base station of claim 33 , wherein to use the communications link channel having the full channel bandwidth for the communications link to the user device the control system is adapted to use −X decibel (dB) power backoff for the communications link to the user device.

35. The base station of claim 17 , wherein the downlink channel is an orthogonal frequency division multiple access (OFDMA) channel.

36. The base station of claim 18 , wherein the uplink channel is a single-carrier frequency division multiple access (SC-FDMA) channel.

37. The base station of claim 16 , wherein the base station serves a cell of the cellular communications network including a plurality of sectors, each sector of the plurality of sectors is assigned a different set of sub-carrier frequencies for use with power boost.

38. The base station of claim 16 , the control system adapted to transmit a message to the user device, the message configuring the user device to report a plurality of sub-band channel quality indications.

39. The base station of claim 16 , wherein determining whether a power boost is needed is at least partially based on the received the plurality of sub-band channel quality indices.

40. The base station of claim 16 , the control system adapted to allocate the selected sub-carrier frequencies to the user device during one transmit time interval by allocating one or more resource blocks, each resource block corresponding to twelve sub-carrier frequencies.

41. The base station of claim 16 , wherein at least one of the at least one other base station transmits a signal to a second user device using at least a portion of the subset of the plurality of sub-carrier frequencies during one transmit time interval.

42. The base station of claim 16 , the control system adapted to allocate the resource blocks to the user device.

Assignments (7)