BASE STATION AND MOBILE COMMUNICATION METHOD

• US 20090318182A1
• Filed: 06/18/2009
• Published: 12/24/2009
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: NAGATO, Rie, Ishikawa, Yoshihiro
• Granted Patent: US 8,583,124 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/143 Downlink power control
• 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 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading

Abstract

A femto base station according to the present invention includes: a downlink perch channel signal transmission power controller unit configured to change a transmission power of a downlink perch channel signal when a first condition is satisfied; and an uplink reception sensitivity controller unit configured to change an uplink reception sensitivity when a second condition is satisfied after the first condition is satisfied.

Claims

1. A base station comprising:

a downlink perch channel signal transmission power controller unit configured to change a transmission power of a downlink perch channel signal, when a first condition is satisfied; and

an uplink reception sensitivity controller unit configured to change an uplink reception sensitivity, when a second condition is satisfied after the first condition is satisfied.

2. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller unit is configured to determine that the first condition is satisfied and to reduce the transmission power of the downlink perch channel signal, when it is detected that an unregistered mobile station enters a cell under the control of the base station and when a frequency of communication performed by the unregistered mobile station fails to be changed to a frequency other than a frequency used in the base station.

3. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller unit is configured to determine that the first condition is satisfied and to reduce the transmission power of the downlink perch channel signal, when the transmission power of the downlink perch channel signal exceeds a predetermined value.

4. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller unit is configured to determine that the first condition is satisfied and to reduce the transmission power of the downlink perch channel signal, when it is determined that the base station is causing interference to a neighboring base station.

5. The base station according to claim 1, wherein

the uplink reception sensitivity controller unit is configured to determine that the second condition is satisfied after the first condition is satisfied and to reduce the uplink reception sensitivity, when the transmission power of the downlink perch channel signal is reduced by a predetermined value or more.

6. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller unit is configured to determine that the first condition is satisfied and to increase the transmission power of the downlink perch channel signal, when it is detected that an unregistered mobile station leaves a cell under the control of the base station.

7. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller unit is configured to determine that the first condition is satisfied and to increase the transmission power of the downlink perch channel signal, when it is determined that there is no longer a possibility of causing interference to a neighboring base station.

8. The base station according to claim 1, wherein

the downlink perch channel signal transmission power controller is configured to determine that the first condition is satisfied and to increase the transmission power of the downlink perch channel signal, when it is detected that a new neighboring base station is installed.

9. The base station according to any one of claims 6 to 8, wherein

the uplink reception sensitivity controller unit is configured to determine that the second condition is satisfied after the first condition is satisfied and to increase the uplink reception sensitivity, when the transmission power of the downlink perch channel signal is increased by a predetermined value or more.

10. A mobile communication method comprising:

changing, at a base station, a transmission power of a downlink perch channel signal, when a first condition is satisfied; and

changing, at the base station, an uplink reception sensitivity, when a second condition is satisfied after the first condition is satisfied.