System and method for indoor coverage of user equipment terminals

• US 20090061939A1
• Filed: 08/29/2007
• Published: 03/05/2009
• Est. Priority Date: 08/29/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Andersson, Soren, Du, Jiuhui
• Granted Patent: US 8,055,300 B2
• Time in Patent Office: Days
• US Class Current: 455/562.100
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Devices and methods to use base stations to communicate with user equipment (UE) terminals in an indoor setting are disclosed. For example, user equipments such as mobile telephone devices may be used in a building with multiple floors. The building may be supplied with antenna elements organized into antenna groups with each group serving an area of the building—a floor for example. The base station, utilizing the antenna groups, communicates with the UE terminals via one or more radio resources. The base station manages radio resources to communicate with multiple UE terminals. The base station selectively activates and deactivates the antenna groups to reduce multiple access interference and to efficiently utilize the radio resources.

Claims

1. A base station for communicating with one or more user equipment (UE) terminals, comprising:

a plurality of antennas configured to transmit and receive wireless signals, corresponding to radio resources, to and from the UE terminals;

a radio frequency (RF) unit operatively coupled to the plurality of antennas and configured to control power of signals emanating from the plurality of antennas;

a beam forming unit operatively coupled to the RF unit and configured to scale the power of the signal emanating from each antenna by a weight factor for each radio resource; and

a beam controller configured to control the beam forming unit by setting the weight factor for each antenna for each radio resource,

wherein multiple indoor antennas of the plurality of antennas are provided for indoor coverage, where the indoors includes an interior space of a physical structure,

wherein the beam controller is configured to set the weight factor for each indoor antenna for each radio resource to control transmission/reception of the wireless signals for indoor UE terminals reachable by the indoor antenna,

wherein the weight factor for each indoor antenna is one of ON and OFF for each radio resource, and

wherein each radio resource is individually identifiable based on at least one of a frequency, a time slot, or a spreading code.

2. The base station of claim 1,

wherein multiple outdoor antennas of the plurality of antennas are provided outdoors, and

wherein the beam controller is configured to set the weight factor for each outdoor antenna to control a direction and/or a width of wireless signal beams for transmission/reception of the wireless signals for outdoor UE terminals reachable by the outdoor antennas.

3. The base station of claim 2, wherein the weight factor for each outdoor antenna is one of a number of outdoor weight factor values, the number of outdoor weight factor values being three or more.

4. The base station of claim 1, wherein the beam controller is configured to:

monitor an access attempt from an indoor UE terminal through the indoor antennas,

determine which indoor antenna is receiving highest quality signal from the indoor UE terminal,

assign a radio resource to communicate with the indoor UE terminal, wherein the radio resource is different from all other radio resources currently used by all of the indoor antennas for communication with the indoor UE terminals, and

set the weight factor associated with the indoor antenna receiving the highest quality signal to ON for the radio resource and set the weight factors of all other indoor antennas to OFF for the radio resource.

5. The base station of claim 4, wherein the beam controller is configured to assign the radio resource when it determines that the radio resource is available for the indoors.

6. The base station of claim 4,

wherein the indoor antenna is a first indoor antenna, and

wherein the beam controller is configured to:

determine if a second indoor antenna is receiving a higher quality signal from the UE terminal than the first indoor antenna, and

set the weight factor of the second indoor antenna to ON for the radio resource and set the weight factor of the first indoor antenna to OFF when it is determined that the second indoor antenna is receiving the higher quality signal from the UE terminal than the first indoor antenna.

7. The base station of claim 1,

wherein the indoors is divided into a plurality of coverage areas such that each indoor antenna is configured to provide coverage for a corresponding coverage area, and

wherein the beam controller is configured to:

monitor an access attempt from an indoor UE terminal located indoors through the multiple indoor antennas,

determine which indoor antenna is receiving highest quality signal from the UE terminal,

assign a radio resource to communicate with the indoor UE terminal, wherein the radio resource is different from all other radio resources currently used by the indoor antenna receiving the highest quality signal, and

set the weight factor associated with the indoor antenna receiving the highest quality signal to ON for the radio resource.

8. The base station of claim 7,

wherein the indoor antenna receiving the highest signal is a first indoor antenna and the radio resource is a first radio resource, and

wherein the beam controller is configured to:

determine if the first radio resource is available for use by the first indoor antenna,

determine if a second indoor antenna is available when it is determined that the first radio resource is not available for use by the first indoor antenna,

assign a second radio resource to communicate with the indoor UE terminal, wherein the second radio resource is different from all other radio resources currently used by the second indoor antenna, and

set the weight factor associated with the second indoor antenna to ON for the second radio resource.

9. The base station of claim 8, wherein the beam controller is configured to determine that the second indoor antenna is available when a quality of the signal from the indoor UE terminal received by the second indoor antenna is at or above a predetermined threshold level.

10. The base station of claim 1,

wherein the indoors is divided into a plurality of coverage areas such that each indoor antenna is configured to provide coverage for a corresponding coverage area,

wherein the beam controller is configured to:

assign a first radio resource to communicate with a first indoor UE terminal located near or in a first coverage area being covered by a first indoor antenna and set the weight factor of the first indoor antenna to ON for the first radio resource, wherein the first radio resource is different from all other radio resources currently used by the first indoor antenna, and

assign a second radio resource to communicate with a second indoor UE terminal located near or in a first coverage area being covered by a second indoor antenna and set the weight factor of the second indoor antenna to ON for the second radio resource, wherein the second radio resource is different from all other radio resources currently used by the second indoor antenna.

11. The base station of claim 10, wherein the first and second radio resources have the same frequencies, time slots, and spreading codes.

12. The base station of claim 1,

wherein the plurality of coverage areas are grouped into one or more reuse zones,

wherein in each reuse zone comprises two or more coverage areas, and

wherein within each reuse zone, a common set of radio resources are allowed to be reused within the coverage areas of the reuse zone.

13. The base station of claim 11, wherein the beam controller is configured to assign the first and second radio resources to communicate with the first and second indoor UE terminals, respectively, when a signal quality from the first indoor UE terminal received by the second indoor antenna is below a predetermined threshold level and a signal quality from the second indoor UE terminal received by the first indoor antenna is below the predetermined threshold level.

14. The base station of claim 10,

wherein the radio resource is a first radio resource, and

wherein the beam controller is configured to:

determine whether the second UE terminal is near or in the first coverage area,

assign a third radio resource, different from the first radio resource, when it is determined that the second UE terminal is near or in the first coverage area,

set the weight factor of the first indoor antenna to ON for the third radio resource, and

set the weight factor of the second indoor antenna to OFF for the second radio resource.

15. The base station of claim 1, wherein the beam controller is configured to:

monitor an access attempt from an indoor UE terminal through the multiple indoor antennas,

determine whether a signal quality from the indoor UE terminal received by at least one indoor antenna is at a predetermined threshold level or higher,

assign a radio resource to communicate with the indoor UE terminal when it is determined that there is at least one indoor antenna that receives the signal quality at the predetermined threshold level or higher, wherein the radio resource is different from all other radio resources currently used by all of the indoor antennas for communication with the indoor UE terminals, and

set the weight factor to ON for the radio resource for each indoor antenna that is determined to receive the signal quality at the predetermined threshold level or higher and set the weight factors of all other indoor antennas to OFF for the radio resource.

16. The base station of claim 1, wherein the beam controller is configured to:

selectively set the weight factors for the indoor antennas for dedicated communication with individual indoor UE terminals through dedicated channels, and

set the weight factors for multiple indoor antennas to ON for broadcast communication with indoor UE terminals through a broadcast channel.

17. The base station of claim 1, wherein in one or more of the indoor antennas is a physically elongated or a physically extended type.

18. The base station of claim 1, wherein in one or more of the indoor antennas includes a plurality of antenna elements.

19. The base station of claim 18, wherein each of the plurality of antenna elements of at least one indoor antenna are polarized differently from other antenna elements of the same plurality of antenna elements.

20. The base station of claim 1, wherein in one or more of the indoor antennas is a leaky cable.

21. The base station of claim 1, wherein in one or more of the indoor antennas are active antennas.

22. A method for communication between a base station and one or more user equipment (UE) terminals, wherein the base station comprises a plurality of antennas configured to transmit and receive wireless signals, corresponding to radio resources, to and from the UE terminals, a radio frequency (RF) unit operatively coupled to the plurality of antennas and configured to control power of signals emanating from the plurality of antennas, a beam forming unit operatively coupled to the RF unit and configured to scale the power of the signal emanating from each antenna by a weight factor for each radio resource, and a beam controller configured to control the beam forming unit, wherein multiple indoor antennas of the plurality of antennas are provided for indoor coverage where the indoors includes an interior space of a physical structure, the method comprising:

setting the weight factor for each indoor antenna for each radio resource to control transmission/reception of the wireless signals for indoor UE terminals reachable by the indoor antenna,

wherein the weight factor for each indoor antenna is one of ON and OFF for each radio resource, and

wherein each radio resource is individually identifiable based on at least one of a frequency, a time slot, or a spreading code.

23. The method of claim 22, further comprising:

monitoring an access attempt from an indoor UE terminal through the indoor antennas;

determining which indoor antenna is receiving highest quality signal from the indoor UE terminal;

assigning a radio resource to communicate with the indoor UE terminal, wherein the radio resource is different from all other radio resources currently used by all of the indoor antennas for communication with the indoor UE terminals; and

setting the weight factor associated with the indoor antenna receiving the highest quality signal to ON for the radio resource and setting the weight factors of all other indoor antennas to OFF for the radio resource.

24. The method of claim 22, wherein the indoors is divided into a plurality of coverage areas such that each indoor antenna is configured to provide coverage for a corresponding coverage area, the method further comprising:

monitoring an access attempt from an indoor UE terminal located indoors through the multiple indoor antennas;

determining which indoor antenna is receiving highest quality signal from the UE terminal; and

assigning a radio resource to communicate with the indoor UE terminal, wherein the radio resource is different from all other radio resources currently used by the indoor antenna receiving the highest quality signal, and

setting the weight factor associated with the indoor antenna receiving the highest quality signal to ON for the radio resource.

25. A computer readable medium in which a program is stored for controlling a base station to communicate with one or more user equipment (UE) terminals, wherein the base station comprises a plurality of antennas configured to transmit and receive wireless signals, corresponding to radio resources, to and from the UE terminals, a radio frequency (RF) unit operatively coupled to the plurality of antennas and configured to control power of signals emanating from the plurality of antennas, a beam forming unit operatively coupled to the RF unit and configured to scale the power of the signal emanating from each antenna by a weight factor for each radio resource, and a beam controller configured to control the beam forming unit, wherein multiple indoor antennas of the plurality of antennas are provided for indoor coverage where the indoors includes an interior space of a physical structure, the program comprising instructions for:

setting the weight factor for each indoor antenna for each radio resource to control transmission/reception of the wireless signals for indoor UE terminals reachable by the indoor antenna,

wherein the weight factor for each indoor antenna is one of ON and OFF for each radio resource, and

wherein each radio resource is individually identifiable based on at least one of a frequency, a time slot, or a spreading code.