Performing a power boost in a wireless communication system

1. A user device in a cellular communications network, comprising:

a transceiver providing a communications link between the user device and a base station, the user device 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 processor associated with the transceiver and adapted to:

transmit a wideband channel quality index to the base station;

transmit a plurality of sub-band channel quality indices to the base station;

in response to a determination that a power boost is needed for a 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 between the user device and the base station 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 determination that a power boost is needed for the communications link between the base station and the user device is based on the wideband channel quality index;

wherein the subset of the plurality of sub-carrier frequencies are determined based at least in part on the plurality of sub-band channel quality indices; and

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

2. The user device of claim 1 , wherein the communications link channel is a downlink channel and the communications link is a downlink.

3. The user device of claim 2 , wherein the downlink channel is an orthogonal frequency division multiple access (OFDMA) channel.

4. The user device of claim 1 , wherein the communications link channel is an uplink channel and the communications link is an uplink.

5. The user device of claim 4 , wherein the uplink channel is a single-carrier frequency division multiple access (SC-FDMA) channel.

6. The user device of claim 1 , wherein the processor is adapted to receive a message from the base station, the message configuring the user device to report a plurality of sub-band channel quality indications.

7. The user device of claim 1 , wherein the processor is 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.

8. The user device of claim 1 , wherein the determination that a power boost is needed comprises a determination that a power boost is needed if the communications link signal-to-interference-plus-noise ratio (SINR) is less than a predetermined threshold.

9. The user device of claim 8 , wherein the predetermined threshold is a minimum SINR needed to maintain a communications link with the base station plus a margin.

10. The user device of claim 1 , wherein the processor is adapted to:

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

use the number of sub-carrier frequencies during a transmit time interval for the communications link between the user device and the base station.

11. A method of operating a user device in a cellular communications network to provide a communications link between the user device and a base station, the user device 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; the method comprising:

transmitting a wideband channel quality index to the base station;

transmitting a plurality of sub-band channel quality indices to the base station;

in response to a determination that a power boost is needed for a 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 between the user device and the base station 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 determination that a power boost is needed for the communications link between the base station and the user device is based on the wideband channel quality index;

wherein the subset of the plurality of sub-carrier frequencies are determined based at least in part on the plurality of sub-band channel quality indices; and

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

12. The method of claim 11 , 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 11 , 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. The method of claim 11 , comprising receiving a message from the base station, the message configuring the user device to report a plurality of sub-band channel quality indications.

17. The method of claim 11 , 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.

18. The method of claim 11 , wherein the determination that a power boost is needed comprises a determination that a power boost is needed if the communications link signal-to-interference-plus-noise ratio (SINR) is less than a predetermined threshold.

19. The method of claim 18 , wherein the predetermined threshold is a minimum SINR needed to maintain a communications link with the base station plus a margin.

20. The method of claim 11 , wherein using a subset of the plurality of sub-carrier frequencies of the communications link channel as a reduced bandwidth channel for the communications link between the user device and the base station comprises:

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

using the number of sub-carrier frequencies for the communications link between the user device and the base station.