Controller for selecting antenna for multiple-input/multiple-output communication

• US 8,565,825 B2
• Filed: 06/02/2009
• Issued: 10/22/2013
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Miyamoto, Shoichi
• Primary Examiner(s): Wozniak, James
• Assistant Examiner(s): WOO, KUO-KONG
• Application Number:
  US12/476,635
• Publication Number:
  US 20090239523A1
• Time in Patent Office: 1,603 Days
• Field of Search: 455/277.2, 455/562.1, 455/69, 455/423, 370/312, 370/350
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0495 using overlapping sectors in the same base station to implement MIMO for antennas
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas

Abstract

A base station apparatus for performing radio communication with a mobile station in a cell having a plurality of sectors performs a MIMO transmission using an antenna selected from among the antennas provided in each of two sectors when the mobile station moves in the vicinity of the boundary between the sectors. A base station apparatus for performing the radio communication with a mobile station in a cell having no sector structure performs a MIMO transmission using two or more antennas selected from among the antennas when the mobile station moves.

Claims

1. A base station apparatus which performs radio communications in a multiple-input/multiple-output transmission with a mobile station in a cell having a plurality of sectors, the base station apparatus comprising:

a plurality of antennas provided for each of the plurality of sectors; and

a controller to compare quality information of a signal received by the mobile station from each of the antennas with a threshold, select a first antenna from among the antennas, provided for a first sector of two sectors, having the quality information exceeding the threshold and a second antenna from among the antennas, provided for a second sector of the two sectors, having the quality information exceeding the threshold when the mobile station moves in a vicinity of a boundary of the two sectors, and select a multiple-input/multiple-output transmission using the selected first and second antennas.

2. The base station apparatus according to claim 1, wherein

the controller selects a transmission by a fast cell selection or soft handover unless there is a plurality of antennas having the quality information exceeding the threshold.

3. The base station apparatus according to claim 2, wherein

the controller adjusts the threshold according to information about a Doppler frequency or a delay spread of the signal received by the mobile station from each antenna.

4. The base station apparatus according to claim 1, wherein:

the controller includes a first scheduler to manage the first antenna of the first sector from which the mobile station moves, and a second scheduler to manage the second antenna of the second sector to which the mobile station moves;

the first scheduler inquires of the second scheduler about whether or not the second antenna of the second sector is available, and selects a multiple-input/multiple-output transmission using the second antenna when the second antenna is available.

5. A base station apparatus which performs radio communications in a multiple-input/multiple-output transmission with a mobile station in a cell having no sector configuration, the base station apparatus comprising:

a plurality of antennas provided corresponding to the cell having no sector configuration; and

a controller to compare quality information of a signal received by the mobile station from each antenna with a threshold, select two or more antennas from among the antennas having the quality information exceeding the threshold when the mobile station moves, and select a multiple-input/multiple-output transmission using the selected antennas, wherein;

the controller comprises a first scheduler to manage an antenna in communications with the mobile station in the plurality of antennas, and a second scheduler to manage a newly selected antenna; and

the first scheduler inquires of the second scheduler whether or not the newly selected antenna is available, and selects a multiple-input/multiple-output transmission using the newly selected antenna if the newly selected antenna is available.

6. The base station apparatus according to claim 5, wherein

the controller adjusts the threshold according to information about a Doppler frequency or a delay spread of the signal received by the mobile station from each antenna.

7. A communication method for performing radio communications in a multiple-input/multiple-output transmission with a mobile station in a cell having a plurality of sectors, the communication method comprising:

comparing quality information of a signal received by the mobile station from each of a plurality of antennas provided for each of the plurality of sectors with a threshold;

selecting a first antenna from among the antennas, provided for a first sector of two sectors, having the quality information exceeding the threshold and a second antenna from among the antennas, provided for a second sector of the two sectors, having the quality information exceeding the threshold when a mobile station moves in a vicinity of a boundary of the two sectors; and

performing a multiple-input/multiple-output transmission using the selected first and second antennas.