Communication system and communication method

• US 20030013475A1
• Filed: 08/27/2002
• Published: 01/16/2003
• Est. Priority Date: 01/31/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yoshimura, Takehiro
• Granted Patent: US 7,349,712 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

One power control means 14 controls a transmitting power according to a control command to a mobile terminal which accesses one task when radio communication is performed with the mobile terminals in the corresponding sector, and a power control unit 15 gives a control command to each of a plurality of power control means 14 to collectively control the transmitting power to mobile terminals in a plurality of sectors, thereby for accomplishing reduction of interference and elimination of traffic maldistribution in a cell consisting of a plurality of sectors when radio communication is performed with mobile terminals for each sector.

Claims

1. A communication system comprising;

a power control means for controlling a transmitting power according to a control command to a mobile terminal which accesses one radio area when radio communication is performed between the mobile terminal in said one radio area; and

a collective control means for giving said control command to each of a plurality of said power control means to collectively control the transmitting power to mobile terminals in a plurality of said radio areas.

2. The communication system according to claim 1, wherein said power control means is a power computing unit for computing the transmitting power according to a control command to a mobile terminal accessing one sector of a cell consisting of plurality of sectors when radio communication is performed with said mobile terminals in said one sector, and said collective control means is a base station for accommodating a plurality of power control means and giving said control command to each of plurality of said power control means to collectively control the transmitting power to mobile terminals in said cell.

3. The communication system according to claim 1, wherein said power control means is a base station for controlling the transmitting power according to a control command to a mobile terminal accessing one cell when radio communication is performed with said mobile terminals in said one cell, and said collective control means is a radio network control apparatus for accommodating a plurality of base stations and giving said control command to each of plurality of said base stations to collectively control the transmitting power to mobile terminals in a plurality of said cells.

4. The communication system according to claim 1, wherein said power control means controls the transmitting power to a mobile terminal for each period of a slot which is a predetermined amount of transmit-receive data, or of a frame consisting of a plurality of slots, for a common pilot channel transmitting power given from said collective control means.

5. The communication system according to claim 1, wherein said collective control means is notified of a value of the number of mobile terminals received by each power control means, and determines the control command to be given to each power control means based on said notified value.

6. The communication system according to claim 1, wherein said collective control means gives said control command to each power control means so as to prevent the occurrence of absence of transmitting power between adjacent radio areas and overlapping of transmitting power between the adjacent radio areas in a plurality of collectively controlled radio areas.

7. The communication system according to claim 6, wherein said collective control means grasps information on a common pilot channel transmitting power in each power control means, and controls a reference signal to interference power ratio and a reference number of random access channels in said each power control means.

8. The communication system according to claim 7, wherein the collective control means defines a range of the maximum value and the minimum value of the common pilot channel transmitting power in each power control means, and if any accommodated power control means autonomously performs a power control in the corresponding radio area, it controls the common pilot channel transmitting power within said defined range for a power control means corresponding to the radio areas adjacent to said radio area.

9. A communication method for giving a control command to a power control means performing radio communication with mobile terminals in one radio area to control a transmitting power to each mobile terminals accessing said one radio area, thereby for collectively controlling the transmitting power to mobile terminals in a plurality of radio areas.

10. The communication method according to claim 9, wherein said power control means controls the transmitting power to the mobile terminal for each period of a slot which is a predetermined amount of transmit-receive data, or of a frame consisting of a plurality of slots, for a common pilot channel transmitting power given from a superordinate.

11. The communication method according to claim 9, wherein upon notification of a value of the number of mobile terminals received by each of a plurality of said power control means, a control command to be given to each power control means is determined based on said notified value.

12. The communication method according to claim 9, wherein said control command is given to each of said plurality of power control means so as to prevent the occurrence of absence of transmitting power between adjacent radio areas and overlapping of transmitting power between the adjacent radio areas in a plurality of collectively controlled radio areas.

13. The communication method according to claim 12, wherein information on a common pilot channel transmitting power in each of said plurality of power control means are grasped to control a reference signal to interference power ratio and a reference number of random access channels in each power control means.

14. The communication method according to claim 13, wherein a ranges of the maximum value and minimum value of the common pilot channel transmitting power in each of said plurality of power control means are defined, and if any power control means autonomously performs a power control in the corresponding radio area, the common pilot channel transmitting power is controlled within said defined ranges for the power control means corresponding to the radio areas adjacent to said radio area.