Wireless control apparatus and communication method

• US 8,229,418 B2
• Filed: 07/24/2006
• Issued: 07/24/2012
• Est. Priority Date: 07/25/2005
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Mori, Shinichi, Umeda, Narumi, Sugiyama, Takatoshi
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): Chughtai, Sarwat
• Application Number:
  US11/491,283
• Publication Number:
  US 20070021151A1
• Time in Patent Office: 2,192 Days
• Field of Search: 370/334, 370/310, 370/331, 370/332, 455/561.1, 455/550.1, 455/63.4, 455/63.1, 455/422.1, 455423-424, 455/428, 455/432.1, 455/436, 455/452.2, 455/453, 455524-525, 455/67.11, 455/67.16
• US Class Current: 455/424
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A wireless control apparatus is disclosed that forms and controls an area of a base station according to an antenna pattern. The wireless control apparatus includes an area formation information gathering part that gathers area formation information pertaining to area formation of a neighboring base station; and an antenna pattern control part that controls and directs at least one of a main lobe, a side lobe, and a null point between the main lobe and the side lobe of the antenna pattern based on the area formation information to reduce frequency interference between a current cell formed by a current base station and a neighboring cell formed by the neighboring base station.

Claims

1. A wireless control apparatus of a wireless communication system including a base station and a mobile station, the mobile station configured to perform handover for changing the base station for communication in response to the mobile station moving from one cell to another cell, the wireless control apparatus forming and controlling an area of the base station according to an antenna pattern, the apparatus comprising:

a receiving unit that receives information from the mobile station, the information relating to a neighboring base station corresponding to a handover destination candidate;

an adjacency calculating part that calculates adjacency between a current cell and a neighboring cell by accumulating the information of the neighboring base station corresponding to the handover destination candidate, the information being received by the receiving unit; and

an antenna pattern control part that controls and directs at least one of a main lobe, a side lobe, and a null point between the main lobe and the side lobe of the antenna pattern based on the adjacency to reduce frequency interference between a current cell formed by a current base station and a neighboring cell formed by the neighboring base station, wherein

the adjacency calculating part increases an adjacency counter value by a predetermined value in response to an active set including a cell of the base station as a main branch being changed, the adjacency counter value indicating the adjacency between the cell of the base station and the cell of the corresponding neighboring base station, the base station being included in the information that is received by the receiving unit and that relates to the neighboring base station corresponding to a handover destination candidate, the main branch being the base station transmitting a common pilot channel or a common control channel with the highest reception level, the active set referring to a combination of the main branch and a certain number of major branches having small differences from the highest reception level, and

wherein the antenna pattern control part controls at least one of an antenna pattern tilt angle and an antenna pattern azimuth of at least one of the current base station and the neighboring base stations based on a comparison of the adjacency counter values.

2. The wireless control apparatus as claimed in claim 1, wherein

the adjacency represents an extent to which an electromagnetic space is shared between the current cell and the neighboring cell, and

the antenna pattern control part controls and directs at least one of the main lobe, the side lobe, and the null point between the main lobe and the side lobe of the antenna pattern based on the adjacency to reduce frequency interference between the current cell and the neighboring cell.

5. The wireless control apparatus as claimed in claim 2, wherein the adjacency calculating part calculates the adjacency based on the adjacency counter value.

6. The wireless control apparatus as claimed in claim 5, further comprising:

a wireless resource monitoring part that determines a state of wireless resources;

wherein the antenna pattern control part controls and directs at least one of the main lobe, the side lobe, and the null point between the main lobe and the side lobe of the antenna pattern based on the state of wireless resources to reduce frequency interference between the current cell and the neighboring cell.

7. The wireless control apparatus as claimed in claim 6, wherein

the antenna pattern control part controls an antenna pattern tilt angle of at least one of the current base station and the neighboring base station based on at least one of the adjacency and the state of wireless resources.

8. The wireless control apparatus as claimed in claim 7, wherein

the antenna pattern control part controls an antenna pattern azimuth of at least one of the current base station and the neighboring base station based on at least one of the adjacency and the state of wireless resources.

9. The wireless control apparatus as claimed in claim 8, wherein

the adjacency calculating part determines the main branch forming a corresponding neighboring cell from the neighboring base stations;

and

the antenna pattern control part controls each of the antenna pattern tilt angle and the antenna pattern azimuth of at least one of the current base station and the neighboring base stations based on the adjacency counter values.

10. The wireless control apparatus as claimed in claim 8, wherein

the adjacency calculating part identifies a change in an active set including the main branch and the major branch forming one or more corresponding neighboring cells;

and

the antenna pattern control part controls each of the antenna pattern tilt angle and the antenna pattern azimuth of at least one of the current base station and the neighboring base stations based on the adjacency counter values.

11. The wireless control apparatus as claimed in claim 8, wherein

the adjacency calculating part determines a change in a monitored set including the main branch and one or more of the neighboring base stations as handover destination candidates forming one or more corresponding neighboring cells;

and

the antenna pattern control part controls each of the antenna pattern tilt angle and the antenna pattern azimuth of at least one of the current base station and the neighboring base stations based on the adjacency counter values.

3. A communication method implemented using a wireless control apparatus of a mobile communication system including a base station and a mobile station, the mobile station configured to perform handover for changing the base station for communication in response to the mobile station moving from one cell to another cell, the wireless control apparatus forming and controlling an area of a base station according to an antenna pattern, the method comprising the steps of:

receiving an uplink wireless channel from the mobile station;

receiving information from the mobile station, the information relating to a neighboring base station corresponding to a handover destination candidate;

calculating adjacency between a current cell and a neighboring cell by accumulating the information of the neighboring base station corresponding to the handover destination candidate, the information being received from the mobile station;

controlling and directing at least one of a main lobe, a side lobe, and a null point between the main lobe and the side lobe of the antenna pattern to reduce frequency interference between the current cell formed by a current base station and the neighboring cell formed by the neighboring base station;

increasing an adjacency counter value by a predetermined value in response to an active set including a cell of the base station as a main branch being changed, the adjacency counter value indicating the adjacency between the cell of the base station and the cell of the corresponding neighboring base station, the base station being included in the information that is received by the receiving and that relates to the neighboring base station corresponding to a handover destination candidate, the main branch being the base station transmitting a common pilot channel or a common control channel with the highest reception level, the active set referring to a combination of the main branch and a certain number of major branches having small differences from the highest reception level, and

controlling at least one of an antenna pattern tilt angle and an antenna pattern azimuth of at least one of the current base station and the neighboring base stations based on a comparison of the adjacency counter values.

4. The communication method as claimed in claim 3, wherein

the adjacency represents an extent to which an electromagnetic space is shared between the current cell and the neighboring cell, and

the controlling step includes controlling and directing at least one of the main lobe, the side lobe, and the null point of the antenna pattern based on the adjacency.

12. The communication method as claimed in claim 4, wherein

in the step of calculating the adjacency, the calculation is based on the adjacency counter value.

13. The communication method as claimed in claim 12, further comprising the step of:

determining and monitoring a state of wireless resources;

wherein the controlling step includes controlling and directing at least one of the main lobe, the side lobe, and the null point of the antenna pattern based on the state of the wireless resources.

14. The communication method as claimed in claim 13, further comprising the step of:

controlling an antenna pattern tilt angle of at least one of the current base station and the neighboring base station based on at least one of the adjacency and the state of wireless resources.

15. The communication method as claimed in claim 14, further comprising the step of:

controlling an antenna pattern azimuth of at least one of the current base station and the neighboring base station based on at least one of the adjacency and the state of the wireless resources.