Methods and arrangements in a wireless communication system

1. A method in a network node, the method comprising:

configuring a wireless terminal with at least two power offset values, wherein at least one of the at least two power offset values is based on a cell selection offset which is applied to extend the range of a neighboring cell interfered by the network node; and

transmitting a downlink scheduling assignment for a subframe to a wireless terminal, wherein the downlink scheduling assignment is comprised in control information, and wherein the control information further comprises an indication of which one of the power offset values is used or will be used for data transmission in the subframe relative to reference signal transmission,

wherein transmitting the downlink scheduling assignment comprises setting one bit in the control information as the indication.

2. The method of claim 1 , wherein a first one of the power offset values is for use in fall-power subframes, and a second one of the power offset values is for use in reduced-power subframes.

3. The method of claim 1 , where the power offset value which is based on the cell selection offset is proportional to the cell selection offset value.

4. The method of claim 1 , further comprising transmitting data in the subframe using the indicated power offset value.

5. The method of claim 1 , further comprising selecting one of the power offset values to use for transmission of data to the wireless terminal.

6. A method in a network node, the method comprising:

configuring a wireless terminal with at least two power offset values, wherein at least one of the at least two power offset values is based on a cell selection offset which is applied to extend the range of a neighboring cell interfered by the network node;

selecting a downlink control information format out of at least two downlink control information formats;

responsive to selecting a first one of the downlink control information formats, transmitting control information comprising an indication of a transmit power offset value that will be used for data in the subframe, and transmitting data in the subframe with the indicated transmit power offset value; and

responsive to selecting a second one of the downlink control information formats, transmitting control information without an indication of a transmit power offset value, and transmitting data in the subframe with a transmit power offset value according to a defined pattern, the defined pattern comprising a first subframe subset corresponding to a first one of the at least two power offset values and a second subframe subset corresponding to a second one of the at least two power offset values,

wherein the control information comprises a downlink scheduling assignment for a subframe to a wireless terminal and an indication of which one of the power offset values is used or will be used for data transmission in the subframe relative to reference signal transmission.

7. The method of claim 1 , further comprising:

configuring a first subframe subset for channel state information measurements, comprising signaling an indication to the wireless terminal of a first transmit power offset value of the at least two power offset values used for transmitting data in the subframes comprised in the first subframe subset, and

configuring a second subframe subset for channel state information measurements, comprising signaling an indication to the wireless terminal of a second transmit power offset value of the at least two power offset values used for transmitting data in the subframes comprised in the second subframe subset.

8. The method of claim 7 , wherein the second transmit power offset value is different from the first transmit power offset value.

9. The method of claim 1 , wherein configuring the wireless terminal with the at least two power offset values comprises:

signaling a first parameter from which a first one of the at least two power offset values is derivable.

10. The method of claim 9 , wherein configuring the wireless terminal with the at least two power offset values further comprises:

signaling a second parameter from which a second one of the at least two power offset values is derivable.

11. A method in a wireless terminal, the method comprising:

receiving at least two power offset values, or information from which the at least two power offset values can be derived;

receiving a downlink assignment for a subframe, wherein the downlink assignment is comprised in control information;

responsive to the control information comprising a first format, applying a power offset corresponding to a power offset value of the at least two power offset values indicated in the control information;

responsive to the control information comprising a second format, applying a power offset corresponding to a power offset value of the at least two power offset values according to a defined pattern, the defined pattern comprising a first subframe subset corresponding to a first one of the at least two power offset values and a second subframe subset corresponding to a second one of the at least two power offset values; and

demodulating data received in the subframe using the applied transmit power offset value.

12. The method of claim 11 , wherein the step of demodulating data further comprises:

a channel estimate based on at least one demodulation reference signal received in the subframe; and

demodulating the data using the channel estimate, wherein the channel estimate is scaled according to the applied power offset value.

13. A wireless terminal comprising radio circuitry and processing circuitry, wherein the processing circuitry is configured to:

receive, via the radio circuitry, at least two power offset values, or information from which the at least two power offset values can be derived;

receive, via the radio circuitry, a downlink assignment for a subframe, wherein the downlink assignment is comprised in control information;

responsive to the control information comprising a first format, apply a power offset corresponding to a power offset value of the at least two power offset values indicated in the control information;

responsive to the control information comprising a second format, apply a power offset corresponding to a power offset value of the at least two power offset values according to a defined pattern, the defined pattern comprising a first subframe subset corresponding to a first one of the at least two power offset values and a second subframe subset corresponding to a second one of the at least two power offset values; and

demodulate data received in the subframe using the applied transmit power offset value.

14. The method of claim 1 , wherein configuring the wireless terminal with the at least two power offset values comprises signaling, from the network node to the wireless terminal, a first UE-specific parameter and a first cell-specific parameter that define a first one of the at least two power offset values.

15. The method of claim 14 , wherein configuring the wireless terminal with the at least two power offset values further comprises signaling, from the network node to the wireless terminal, a second UE-specific parameter and a second cell-specific parameter that define a second one of the at least two power offset values.

16. The method of claim 14 , wherein configuring the wireless terminal with the at least two power offset values further comprises signaling a delta value, relative to the first one of the power offset values, that defines a second one of the at least two power offset values.

17. The method of claim 1 , wherein ones of the at least two power offset values correspond to a difference of a respective energy per resource element of data transmission to an energy per resource element of reference signal transmission.

18. The method of claim 11 , wherein at least one of the at least two power offset values is based on a cell selection offset which is applied to extend the range of a neighboring cell interfered by a network node.

19. The method of claim 18 , wherein the at least one power offset value which is based on the cell selection offset is proportional to the cell selection offset value.