METHODS AND ARRANGEMENTS IN A WIRELESS COMMUNICATION SYSTEM

• US 20120046039A1
• Filed: 05/20/2009
• Published: 02/23/2012
• Est. Priority Date: 05/20/2009
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hagerman, Bo, Asplund, Henrik, Simonsson, Arne
• Granted Patent: US 8,320,926 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04W 72/51 based on terminal or device properties

Abstract

The present invention relates to methods and arrangements in a wireless communication system that enable the allocation of resources to UEs based on measurements of their antenna polarization, in order to suppress the interference between different UEs at a very low overhead cost. This is achieved by a solution where the scheduling unit retrieves information about the polarization of the UE antenna configurations, and based on this information allocates radio resources to the different UEs, with the aim to minimize the interference. The scheduling unit may retrieve the information from the RBSs or from the UEs. The RBS and the UE will determine the polarization and transmit information regarding this polarization to the scheduling unit. The scheduling unit coordinates the allocation of resources with other scheduling units if necessary.

Claims

1. A method for resource allocation in a wireless communication system comprising at least one radio base station serving two or more user equipments, each user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, wherein at least one scheduling unit controls the allocation of radio resources to said user equipments, said method comprising the following steps, performed by a scheduling unit:

retrieving information regarding the polarization of the antenna configuration of at least two of said user equipments, and

allocating resources for said at least two user equipments responsive to the retrieved information.

2. The method according to claim 1, comprising the additional step of coordinating the allocation of resources with a second scheduling unit responsive to the retrieved information, when more than one scheduling unit controls the allocation of resources to said at least two user equipments.

3. The method according to claim 1, wherein:

the step of retrieving information regarding the polarization of the antenna configuration comprises the sub step of retrieving information regarding the polarization of the receiving at least one antenna of said antenna configuration, and

the step of allocating resources comprises the sub step of controlling polarization of the transmitting at least one antenna of at least one radio base station serving said at least two user equipments responsive to the retrieved information.

4. The method according to claim 1, wherein:

the antenna configuration of said at least two user equipments comprises at least one additional transmitting antenna,

the step of retrieving information regarding the polarization of the antenna configuration comprises the sub step of retrieving information regarding the polarization of each of the transmitting antennas of said antenna configuration, and

the step of allocating resources comprises the sub step of controlling the transmitting antenna polarizations of said at least two user equipments responsive to the retrieved information.

5. The method according to claim 3, wherein the sub step of controlling polarization of the transmitting at least one antenna comprises applying transmitting antenna weights.

6. The method according to claim 1, wherein the step of allocating resources comprises the sub step of scheduling two of said at least two user equipments having substantially orthogonal antenna polarizations in the same time or frequency resource.

7. A method for resource allocation in a wireless communication system comprising at least one radio base station serving two or more user equipments, each user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, wherein at least one scheduling unit controls the allocation of radio resources to said user equipments, said method comprising the following steps, performed by a radio base station:

retrieving information regarding the polarization of the antenna configuration of at least two of the served user equipments, and

transmitting the retrieved information to a scheduling unit to cause the scheduling unit to use the retrieved information when allocating resources.

8. The method according to claim 7, wherein the step of retrieving information regarding the polarization of the antenna configuration comprises the sub steps of

determining the polarization of the transmitting antenna of said antenna configuration responsive to a measurement of the uplink signal strength for each radio base station receiving antenna, and

quantizing the determined polarization into one of at least two possible polarization states.

9. The method according to claim 8, wherein the step of retrieving information regarding the polarization of the antenna configuration comprises the further sub step of estimating the polarization state of the receiving antenna of said antenna configuration to be equal to the polarization state of the transmitting antenna of said antenna configuration.

10. The method according to claim 8, wherein the measurement of the uplink signal strength for each radio base station receiving antenna is performed for at least two frequencies.

11. The method according to claim 7, wherein the information regarding the polarization of the antenna configuration is retrieved from each of the served user equipments.

12. The method according to claim 7, wherein the steps of retrieving information regarding the polarization of the antenna configuration and transmitting the retrieved information are performed at regular intervals, or in response to a query from a scheduling unit, or when a defined event occurs.

13. A method for resource allocation in a wireless communication system comprising at least one radio base station serving two or more user equipments, each user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, wherein at least one scheduling unit controls the allocation of radio resources to said user equipments, said method comprising the following steps, performed by a user equipment:

determining the polarization of the antenna configuration, and

forwarding information regarding the determined polarization to a scheduling unit, to cause the scheduling unit to use the forwarded information when allocating resources.

14. The method according to claim 13, wherein the step of determining the polarization of the antenna configuration comprises the sub steps of

determining the polarization of the receiving antenna of said antenna configuration responsive to a measurement of a serving radio base station transmitting antenna specific pilots, and

quantizing the determined polarization into one of at least two possible polarization states, said possible polarization states comprising a vertical polarization state and a horizontal polarization state.

15. The method according to claim 14, wherein said possible polarization states further comprises a mixed polarization state or only one of the vertical and horizontal polarization states.

16. The method according to claim 14, wherein the step of determining the polarization of the antenna configuration comprises the further sub step of estimating the polarization state of the transmitting antenna of said antenna configuration to be equal to the polarization state of the receiving antenna of said antenna configuration.

17. The method according to claim 14, wherein the measurement of the serving radio base station transmitting antenna specific pilots is performed for at least two frequencies.

18. The method according to claim 13, wherein:

the wireless communication system is configured to operate according to 3GPP Long Term Evolution (LTE) and a scheduling unit is co-located with each radio base station, and

the information regarding the determined polarization is forwarded to the scheduling unit in a serving radio base station using a pre-coding matrix indicator PMI.

19. The method according to claim 13, wherein the steps of determining the polarization of the antenna configuration and forwarding information regarding the determined polarization are performed at regular intervals, or in response to a query from the scheduling unit, or when a defined event occurs.

20. A scheduling unit for a wireless communication system, the system comprising at least one radio base station serving two or more user equipments, each user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, said scheduling unit arranged to control the allocation of radio resources to user equipments and comprises:

a retrieving unit for retrieving information regarding the polarization of the antenna configuration of at least two of said user equipments, and

an allocating unit for allocating resources for said at least two user equipments responsive to the retrieved information.

21. The scheduling unit according to claim 20, further comprising a coordinating unit for coordinating the allocation of resources with a second scheduling unit responsive to the retrieved information, when more than one scheduling unit controls the allocation of resources to said at least two user equipments.

22. The scheduling unit according to claim 20, wherein:

the retrieving unit is arranged to retrieve information regarding the polarization of the receiving at least one antenna of said antenna configuration, and

the allocating unit is arranged to control the transmitting antenna polarization(s) of at least one radio base station serving said at least two user equipments responsive to the retrieved information.

23. The scheduling unit according to claim 20, wherein:

the antenna configuration of said at least two user equipments comprises at least one additional transmitting antenna,

the retrieving unit is arranged to retrieve information regarding the polarization of each of the transmitting antennas of said antenna configuration, and

the allocating unit is arranged to control the transmitting antenna polarization(s) of said at least two user equipments responsive to the retrieved information.

24. The scheduling unit according to claim 22, wherein the control of the transmitting antenna polarization comprises applying transmitting antenna weights.

25. The scheduling unit according to claim 20, wherein the allocating unit is arranged to schedule two of said at least two user equipments having substantially orthogonal antenna polarizations in the same time or frequency resource.

26. A radio base station for a wireless communication system, said system comprising a scheduling unit controlling the allocation of radio resources to user equipments, each user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, said radio base station arranged to serve said user equipments and comprises:

a retrieving unit for retrieving information regarding the polarization of the antenna configuration of at least two of the served user equipments, and

a transmitter for transmitting the retrieved information to a scheduling unit to cause the scheduling unit to use the retrieved information when allocating resources.

27. The radio base station according to claim 26, wherein the retrieving unit is arranged to

determine the polarization of the transmitting antenna of said antenna configuration responsive to a measurement of the uplink signal strength for each radio base station receiving antenna, and

quantize the determined polarization into one of at least two possible polarization states.

28. The radio base station according to claim 27, wherein the retrieving unit is further arranged to estimate the polarization state of the receiving antenna of said antenna configuration to be equal to the polarization state of the transmitting antenna of said antenna configuration.

29. The radio base station according to claim 26, wherein the measurement of the uplink signal strength for each radio base station receiving antenna is performed for at least two frequencies.

30. The radio base station according to claim 26, wherein the retrieving unit is arranged to retrieve the information from each of the served user equipments.

31. A user equipment for a wireless communication system, said system comprising at least one radio base station serving user equipments of the system and at least one scheduling unit controlling the allocation of radio resources to the user equipments of the system, said user equipment provided with an antenna configuration comprising a transmitting and a receiving antenna, and the user equipment further comprises:

a determining unit for determining the polarization of the antenna configuration, and

a forwarding unit for forwarding information regarding the determined polarization to a scheduling unit, to cause the scheduling unit to use the forwarded information when allocating resources.

32. The user equipment according to claim 31, wherein the determining unit is arranged to:

determine the polarization of the receiving antenna of said antenna configuration responsive to a measurement of a serving radio base station transmitting antenna specific pilots, and

quantize the determined polarization into one of at least two possible polarization states, said polarization states comprising a vertical polarization state and a horizontal polarization state.

33. The user equipment according to claim 32, wherein said polarization states further comprises a mixed polarization state or only one of the vertical and horizontal polarization states.

34. The user equipment according to claim 32, wherein the determining unit is arranged to estimate the polarization state of the transmitting antenna of said antenna configuration to be equal to the polarization state of the receiving antenna of said antenna configuration.

35. The user equipment according to claim 32, wherein the measurement of the serving radio base station transmitting antenna specific pilots is performed for at least two frequencies.

36. The user equipment according to claim 31, wherein:

the wireless communication system is configured to operate according to 3GPP Long Term Evolution (LTE),

a scheduling unit is co-located with each radio base station, and

the forwarding unit is arranged to forward the information to the scheduling unit in a serving radio base station using a pre-coding matrix indicator, PMI.