RADIO COMMUNICATION SYSTEM, CENTRALIZED STATION, CONTROL STATION APPARATUS, RADIO BASE STATION AND COORDINATED TRANSMISSION METHOD

• US 20120026956A1
• Filed: 07/27/2011
• Published: 02/02/2012
• Est. Priority Date: 07/28/2010
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: BENJEBBOUR, Anass, OKUMURA, Yukihiko, OHWATARI, Yusuke
• Granted Patent: US 8,787,279 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

The radio communication system of the present invention is provided with a cluster pattern determining section 61 that determines the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference with other neighboring clusters less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in a cluster composed of neighboring cells, the each cluster pattern being in different combinations of directional patterns and frequency blocks.

Claims

1. A radio communication system provided with a plurality of radio base stations each forming a cell with a plurality of sectors, comprising:

a cluster pattern determining section configured to determine the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in a cluster composed of neighboring cells, the each cluster pattern being in different combinations of directional patterns and frequency blocks; and

a directional pattern determining section configured to assign directional patterns to the plurality of radio base stations in cluster units for each frequency block based on the cluster pattern determined by the cluster pattern determining section, wherein;

the plurality of radio base stations form directional beams according to the directional pattern in the same time slot and coordinate data transmission between sectors through multiuser MIMO transmission between directional beams of one radio base station and the other radio base station having sectors adjacent to each other in a cluster and facing each other at the same frequency block.

2. The radio communication system according to claim 1, wherein the cluster pattern assigned to each cluster is fixed.

3. The radio communication system according to claim 1, wherein the cluster pattern assigned to the each cluster is dynamically switched according to a situation of inter-cluster interference.

4. A centralized station in a radio communication system provided with a plurality of radio base stations each forming a cell with a plurality of sectors that integrates the radio base stations in units of a cluster composed of neighboring cells, comprising:

a cluster pattern determining section configured to determine the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in the cluster, the each cluster pattern being in different combinations of directional patterns and frequency blocks;

a directional pattern determining section configured to assign a directional pattern to the plurality of radio base stations in cluster units for each frequency block based on the cluster pattern determined by the cluster pattern determining section;

a signal distribution section configured to distribute to a plurality of radio base stations of the same cluster data signals for coordinated transmission within the cluster; and

a precoding section configured to precode the distributed data signals by the signal distribution section, the precoded data is transmitted on directional beams over the directional pattern assigned for each frequency block by the directional pattern determining section.

5. A control station apparatus in a radio communication system provided with a plurality of radio base stations each forming a cell with a plurality of sectors that manages a centralized station that integrates the radio base stations in units of a cluster composed of neighboring cells, comprising:

a cluster pattern determining section configured to determine the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in the cluster, the each cluster pattern being in different combinations of directional patterns and frequency blocks;

a notifying section configured to notify the each centralized station of the cluster pattern determined by the cluster pattern determining section.

6. A radio base station that forms a cell with a plurality of sectors together with other neighboring radio base stations in a radio communication system, comprising:

a cluster pattern determining section configured to determine the assignment of each cluster pattern to each cluster so as to suppress inter- cluster interference with other neighboring clusters less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in a cluster composed of neighboring cells, the each cluster pattern being indifferent combinations of directional patterns and frequency blocks;

a directional pattern determining section configured to assign a directional pattern to the base station for each frequency block based on the cluster pattern determined by the cluster pattern determining section; and

a precoding section configured to form beams within a directional pattern assigned for each frequency block by the directional pattern determining section using multiuser MIMO precoding to transmit data signals in a coordinated manner in the cluster.

7. A coordinated transmission method for a radio communication system provided with a plurality of radio base stations each forming a cell with a plurality of sectors, comprising the steps of:

determining the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in a cluster composed of neighboring cells, the each cluster pattern being in different combinations of directional patterns and frequency blocks; and

assigning directional patterns to the plurality of radio base stations in cluster units for each frequency block based on the determined cluster pattern, wherein;

the plurality of radio base stations form directional beams according to the directional pattern in the same time slot and coordinate data transmission between sectors through multiuser MIMO transmission between directional beams of one radio base station and the other radio base station having sectors adjacent to each other in a cluster and facing each other at the same frequency.