Wireless communication system, base station, radio resource management method, and control program of base station

• US 9,084,202 B2
• Filed: 09/16/2008
• Issued: 07/14/2015
• Est. Priority Date: 10/22/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hamabe, Kojiro, Morita, Motoki
• Primary Examiner(s): Elliott, IV, Benjamin H
• Application Number:
  US12/738,925
• Publication Number:
  US 20100238905A1
• Time in Patent Office: 2,492 Days
• Field of Search: 370/310.2, 370/311, 370/312, 370/314, 370/318, 370/328, 370/332, 370/335, 370/342, 370/461, 375/346, 342/357.28, 342/357.29, 342/357.4, 342/357.49, 342/357.59, 455/446, 4554561-4566, 455/41.2, 455/513, 455/522, 455/524, 455/525, 455/63.1, 455/67.133, 455/114.2, 4551151-1154, 455/161.3, 4552261-2264
• US Class Current: 1/1
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

To provide appropriate communication quality inside a building regardless of the building penetration loss of the building in which a femto base station is installed while suppressing the interference caused by radio waves leaked outside the building, a femto base station 4 receives a radio signal that passes through a structure and arrives at the installation place of the femto base station 4 (e.g., radio signal transmitted from a Global Positioning System) and estimates the penetration loss L of the structure based on the receiving state of the radio signal. Further, the femto base station 4 performs radio resource management based on an estimation result of the penetration loss L, and communicates with a mobile station 7-2.

Claims

1. A wireless communication system comprising a first base station that performs wireless communication with a mobile station,

wherein the first base station receives an incoming radio signal, estimates a penetration loss of the radio signal caused by a structure located between a radio signal transmission source of the radio signal and the first base station, and performs radio resource management based on the estimated penetration loss of the radio signal, wherein the estimated penetration loss is a loss factor corresponding to a part of a total path loss between the radio signal transmission source and the first base station;

wherein the radio signal transmission source is an apparatus of one of a plurality of artificial satellites constituting a positioning system; and

wherein the radio signal is a positioning signal transmitted from the one of the plurality of artificial satellites.

2. The wireless communication system according to claim 1, wherein the radio resource management includes setting a transmission power of a first common pilot signal used by the first base station to perform communication with the mobile station based on the estimated penetration loss.

3. The wireless communication system according to claim 2, wherein the first base station retains a reference value of a received power of a radio signal exhibited outdoors on ground in advance, and estimates the penetration loss based on a difference between the reference value and a received power level of the radio signal.

4. The wireless communication system according to claim 2, wherein the first base station sets the transmission power such that the transmission power increases with a decrease in a received power of the radio signal.

5. The wireless communication system according to claim 2, wherein

the first base station measures a position based on the positioning signal, and sets the transmission power such that the transmission power increases with an increase in a time required measure a position or with a decrease in accuracy of a measured position.

6. The wireless communication system according to claim 2, wherein the first base station measures a received power or a reception SIR of a second common pilot signal transmitted from a second base station included in the wireless communication system, and sets a transmission power of the first common pilot signal based on a result of the measurement.

7. The wireless communication system according to claim 6, wherein assuming that a reference value of a received power of the radio signal and a measured value of the received power of the radio signal are Pgps_outdoor and Pgps respectively, and that K1 is a constant value greater than zero,

the first base station calculates the transmission power by adding K1 (Pgps_outdoor−

Pgps) to a value determined according to a received power of the second pilot signal.

8. The wireless communication system according to claim 1, wherein the first base station performs radio resource management so that a leak power leaked from at least one of the first base station and the mobile station to outside of the structure becomes substantially invariant.

9. The wireless communication system according to claim 1, wherein the radio signal is a signal whose received power on ground in an outdoor region in which the first base station is installed is substantially invariant regardless of a place.

10. The wireless communication system according to claim 1, wherein the radio resource management includes setting a target received power of an uplink signal used in uplink data transmission from the mobile station in the first base station based on the estimated penetration loss.

11. The wireless communication system according to claim 10, wherein the first base station retains a reference value of a received power of a radio signal exhibited outdoors on ground in advance, and estimates the penetration loss based on a difference between the reference value and a received power level of the radio signal.

12. The wireless communication system according to claim 10, wherein the first base station sets the target received power such that the target received power increases with a decrease in a received power of the radio signal.

13. The wireless communication system according to claim 1, wherein a CDMA mode is used as a wireless access mode.

14. The wireless communication system according to claim 1, wherein, in communication between the first base station and a mobile station, a radio frequency band is divided into a plurality of resource blocks, and information is transmitted by using one or more than one resource block.

15. A base station that is used in a wireless communication system and performs wireless communication with a mobile station, comprising:

a reception unit being configured to receive an incoming radio signal comprising a positioning signal transmitted by a radio signal transmission source which is an apparatus of one of a plurality of artificial satellites constituting a positioning system;

a radio network control unit being configured to estimate a penetration loss of the radio signal, received by the reception unit, caused by a structure located between the radio signal transmission source of the radio signal and the base station and to perform radio resource management based on the estimated penetration loss of the radio signal received by the reception unit, wherein the estimated penetration loss is a loss factor corresponding to a part of a total path loss between the radio signal transmission source and the base station; and

a wireless transmission reception unit being configured to communicate with the mobile station according to control by the radio network control unit.

16. The base station according to claim 15, wherein the radio network control unit sets a transmission power of a first common pilot signal used to perform communication with the mobile station based on the estimated penetration loss.

17. The base station according to claim 16, wherein the radio network control unit retains a reference value of a received power of a radio signal exhibited outdoors on ground in advance, and estimates the penetration loss based on a difference between the reference value and a received power level of the radio signal measured by the reception unit.

18. The base station according to claim 17, wherein

the reception unit performs position measurement based on the positioning signal, and

the radio network control unit sets the transmission power such that the transmission power increases with an increase in a time required for the position measurement or with a decrease in accuracy of a position measured by the position measurement.

19. The base station according to claim 16, wherein a received power or a reception SIR of a second common pilot signal transmitted from a second base station included in the wireless communication system is measured, and the first transmission power is set based on a result of the measurement.

20. The base station according to claim 15, wherein the radio network control unit sets a target received power based on an estimation result of the penetration loss, the target received power being a target value of a received power of an uplink signal used in uplink data transmission from the mobile station.

21. The base station according to claim 15, wherein the radio network control unit performs radio resource management so that a leak power leaked from at least one of the base station and the mobile station to outside of the structure becomes substantially invariant.

22. A radio resource management method used in a wireless communication system and performed by a base station that performs wireless communication with a mobile station, the method comprising:

receiving a radio signal arriving at an installation place of the base station, the radio signal comprising a positioning signal transmitted by a radio signal transmission source which is an apparatus of one of a plurality of artificial satellites constituting a positioning system;

estimating a penetration loss of the radio signal caused by a structure located between the radio signal transmission source of the radio signal and the base station, wherein the estimated penetration loss is a loss factor corresponding to a part of a total path loss between the radio signal transmission source and the base station;

performing radio resource management based on the estimated penetration loss of the radio signal; and

communicating with the mobile station based on a wireless parameter determined by the radio resource management.

23. The radio resource management method according to claim 22,

wherein the wireless parameter is a transmission power of a first common pilot signal used by the base station to perform communication with the mobile station, and

wherein, in the radio resource management, a reference value of a received power of a radio signal exhibited outdoors on ground is retained in advance, so that the penetration loss is estimated based on a difference between the reference value and a received power level of the radio signal, and

a transmission power of the first common pilot signal is set based on an estimation result of the penetration loss.

24. The radio resource management method according to claim 22,

wherein the wireless parameter is a target received power, the target received power being a target value of a received power of an uplink signal used in uplink data transmission from the mobile station, and

wherein, in the radio resource management, a reference value of a received power of a radio signal exhibited outdoors on ground is retained in advance, so that the penetration loss is estimated based on a difference between the reference value and a received power level of the radio signal, and

the target received power is set based on an estimation result of the penetration loss.

25. The radio resource management method according to claim 22,

wherein the wireless parameter is a transmission power of a first common pilot signal used by the base station to perform communication with the mobile station, and

wherein, in the radio resource management, the transmission power is set such that the transmission power increases with an increase in a time required for the position measurement performed based on the positioning signal or with a decrease in accuracy of a position measured by the position measurement.

26. The radio resource management method according to claim 22, wherein radio resource management is performed so that a leak power leaked from at least one of the base station and the mobile station to outside of the structure becomes substantially invariant.

27. A non-transitory computer readable media storing a base station control program that causes a computer to execute control processing for a base station used in a wireless communication system, the base station comprising a wireless transmission reception unit that performs wireless communication with a mobile station, and a reception unit that receives a radio signal arriving at an installation place of the base station, the control processing comprising:

a process of causing the reception unit to receive the radio signal;

a process of estimating a penetration loss of the radio signal caused by a structure located between a radio signal transmission source of the radio signal and the base station, wherein the estimated penetration loss is a loss factor corresponding to a part of a total loss between the radio signal transmission source and the base station;

a process of performing radio resource management based on the estimated penetration loss of the radio signal received by the reception unit; and

a process of causing the wireless transmission reception unit to execute communication with the mobile station based on a wireless parameter determined by the radio resource management;

wherein the radio signal transmission source is an apparatus of one of a plurality of artificial satellites constituting a positioning system; and

wherein the radio signal is a positioning signal transmitted from the one of the plurality of artificial satellites.

28. A wireless communication system comprising a first base station that performs wireless communication with a mobile station, wherein

the first base station receives a radio signal that passes through a structure and arrives at an installation place of the first base station, estimates a penetration loss of the radio signal caused by the structure located between a radio signal transmission source of the radio signal and the first base station, performs radio resource management based on the estimated penetration loss of the radio signal so that a leak power that is leaked from at least one of the first base station and the mobile station to an opposite side to the installation place through the structure becomes substantially invariant, and communicates with the mobile station, wherein the estimated penetration loss is a loss factor corresponding to a past of a total path loss between the radio signal transmission source and the first base station;

wherein the radio signal transmission source is an apparatus of one of a plurality of artificial satellites constituting a positioning system; and

wherein the radio signal is a positioning signal transmitted from the one of the plurality of artificial satellites.

29. A base station that is used in a wireless communication system and performs wireless communication with a mobile station, comprising:

a reception unit which is configured to receive an incoming radio signal that passes through a structure and arrives at an installation place of the base station;

a radio network control unit which is configured to estimate a penetration loss of the radio signal caused by the structure located between a radio signal transmission source of the radio signal and the base station and to perform radio resource management based on the estimated penetration loss of the radio signal so that a leak power that is leaked from at least one of the base station and the mobile station to an opposite side to the installation place through the structure becomes substantially invariant, wherein the estimated penetration loss is a loss factor corresponding to a part of a total path loss between the radio signal transmission source and the base station; and

a wireless transmission reception unit which is configured to communicate with the mobile station according to control by the radio network control unit;

wherein the radio signal transmission source is an apparatus of one of a plurality of artificial satellites constituting a positioning system; and

wherein the radio signal is a positioning signal transmitted from the one of the plurality of artificial satellites.

30. A radio resource management method used in a wireless communication system and performed by a base station that performs wireless communication with a mobile station, the method comprising:

receiving a radio signal arriving at an installation place of the base station;

estimating a penetration loss of the radio signal caused by the structure located between a radio signal transmission source of the radio signal and the base station, wherein the estimated penetration loss is a loss factor corresponding to a part of a total path loss between the radio signal transmission source and the base station;

performing radio resource management based on the estimated penetration loss of the radio signal so that a leak power that is leaked from at least one of the base station and the mobile station to an opposite side to the installation place through the structure becomes substantially invariant; and

performing communication with the mobile station based on a wireless parameter determined by the radio resource management;

wherein the radio signal transmission source is an apparatus of one of a plurality of artificial satellites constituting a positioning system; and

wherein the radio signal is a positioning signal transmitted from the one of the plurality of artificial satellites.