Determination of a preferred beam in a cellular communication network employing signal beam-forming

1. An arrangement for determination of a preferred beam, the arrangement being for a wireless communication device adapted to communicate with a network node of a cellular communication network, wherein the network node is adapted to support a plurality of beams of a signal beam-forming scheme and to communicate with the wireless communication device using at least one beam of the plurality of beams, the arrangement comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the arrangement is operative to:

receive, from the network node, a message indicative of a beam power setting of the plurality of beams, wherein the beam power setting comprises a power offset being applied to at least one beam of the plurality of beams, the power offset being relative to a nominal power setting of the plurality of beams;

perform measurements on measurement signals transmitted by the network node;

determine the preferred beam based on the measurements and the beam power setting; and

transmit, to the network node, a report indicative of the preferred beam.

2. The arrangement of claim 1 , wherein the message indicative of the beam power setting comprises a value of the power offset.

3. The arrangement of claim 1 :

wherein the beam power setting is according to a power envelope of a plurality of predetermined power envelopes; and

wherein the message indicative of the beam power setting comprises an envelope index identifying the power envelope.

4. The arrangement of claim 1 , wherein the instructions are such that the arrangement is operative to:

determine the preferred beam by compensating the measurements based on the beam power setting; and

select the preferred beam based on the compensated measurements.

5. The arrangement of claim 1 :

wherein an extended precoding codebook comprises a plurality of versions of a nominal precoding codebook defining the plurality of beams having the nominal power setting, wherein the plurality of versions define different power offset values; and

wherein the message indicative of the beam power setting comprises indices identifying a subset of entries of the extended precoding codebook.

6. The arrangement of claim 1 , further comprising:

a transmitter configured to transmit the report indicative of the preferred beam; and

a receiver configured to receive the message indicative of the beam power setting.

7. A wireless communication device configured to communicate with a network node of a cellular communication network, wherein the network node is adapted to support a plurality of beams of a signal beam-forming scheme and to communicate with the wireless communication device using at least one beam of the plurality of beams, wherein the wireless communication device comprises:

an arrangement for determination of a preferred beam, the arrangement comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the arrangement is operative to:

receive, from the network node, a message indicative of a beam power setting of the plurality of beams, wherein the beam power setting comprises a power offset being applied to at least one beam of the plurality of beams, the power offset being relative to a nominal power setting of the plurality of beams;

perform measurements on measurement signals transmitted by the network node;

determine the preferred beam based on the measurements and the beam power setting; and

transmit, to the network node, a report indicative of the preferred beam.

8. An arrangement for acquiring an indication of a preferred beam of a wireless communication device, the arrangement being for a network node of a cellular communication network, wherein the network node is adapted to support a plurality of beams of a signal beam-forming scheme and to communicate with the wireless communication device using at least one beam of the plurality of beams, the arrangement comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the arrangement is operative to:

acquire of a beam power setting of the plurality of beams, wherein the beam power setting comprises a power offset being applied to at least one beam of the plurality of beams, the power offset being relative to a nominal power setting of the plurality of beams;

transmit, to the wireless communication device, a message indicative of the beam power setting;

transmit measurement signals; and

receive, from the wireless communication device, of a report indicative of the preferred beam, wherein the preferred beam is determined by the wireless communication device based on the measurement signals and the beam power setting.

9. The arrangement of claim 8 , wherein the instructions are such that the arrangement is operative to select one beam out of the plurality of beams for communication with the wireless communication device based on the received report.

10. The arrangement of claim 8 , wherein the beam power setting approximates a cell radiation power profile of the network node.

11. The arrangement of claim 8 , wherein the beam power setting comprises beams having a power setting that is lower than the nominal power setting if having a direction within a particular angle range.

12. The arrangement of claim 11 , wherein the particular angle range comprises an angle corresponding to a bearing from the network node to a location of a wireless communication device served by a neighboring network node of the cellular communication system.

13. The arrangement of claim 8 , wherein the message indicative of the beam power setting comprises a value of the power offset.

14. The arrangement of claim 8 :

wherein the beam power setting is according to a power envelope of a plurality of predetermined power envelopes; and

wherein the message indicative of the beam power setting comprises an envelope index identifying the power envelope.

15. The arrangement of claim 8 :

wherein an extended precoding codebook comprises a plurality of versions of a nominal precoding codebook defining the plurality of beams having the nominal power setting, wherein the plurality of versions define different power offset values; and

wherein the message indicative of the beam power setting comprises indices identifying a subset of entries of the extended precoding codebook.

16. The arrangement of claim 8 , wherein the arrangement further comprises:

a transmitter configured to transmit the message indicative of the beam power setting and the measurement signals; and

a receiver configured to receive the report indicative of the preferred beam.

17. A network node for a cellular communication network, the network node configured to support a plurality of beams of a signal beam-forming scheme and to communicate with a wireless communication device using at least one beam of the plurality of beams, wherein the network node comprises:

an arrangement for acquiring an indication of a preferred beam of a wireless communication device, the arrangement comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the arrangement is operative to:

acquire of a beam power setting of the plurality of beams, wherein the beam power setting comprises a power offset being applied to at least one beam of the plurality of beams, the power offset being relative to a nominal power setting of the plurality of beams;

transmit, to the wireless communication device, a message indicative of the beam power setting;

transmit measurement signals; and

receive, from the wireless communication device, a report indicative of the preferred beam, wherein the preferred beam is determined by the wireless communication device based on the measurement signals and the beam power setting.