Radio communication system using adaptive array antenna

• US 7,082,321 B2
• Filed: 07/15/2003
• Issued: 07/25/2006
• Est. Priority Date: 02/01/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kuwahara, Mikio, Doi, Nobukazu
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): CHOW, CHARLES CHIANG
• Application Number:
  US10/618,757
• Publication Number:
  US 20040014501A1
• Time in Patent Office: 1,106 Days
• Field of Search: 455/562.1, 455/277.1, 455/277.2, 455/278.1, 455/279.1, 455/69, 455/522, 455/561, 455/550.1, 455/575.1, 455/424, 455/425, 455/456.5, 455/456.6, 455/67.11, 455/67.13, 455/68, 455/422.1, 455/436, 455/439, 455/453, 455/455, 455/456.3, 455/13.4, 455/25, 455/19, 455/63.4, 455/126, 455/275, 455/273, 455/101, 455/575.7, 455/501, 455/506, 370/342, 370/335, 370/320, 370/441, 370/310.2, 370/329, 370/311, 370/278, 370/332, 370/470, 370/333, 370/331, 370/465, 370/474, 370/479, 370/328, 370/340, 370/334, 342/380, 342/383, 342/368, 342/379, 375/267, 375/347, 375/220, 375/141, 375/261, 375/298, 375/300
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0623 Auxiliary parameters, e.g. power control [PCB] or not acknowledged commands [NACK], used as feedback information

Abstract

A radio communication system and method having an array antenna and a weighting arrangement that provides a downlink array weight for a downlink on the basis of information about bearings of a plurality of incoming signals received through a plurality of uplinks, and transmission power control information about transmission data to be transmitted through a downlink.

Claims

1. A transmission control method for a base station which communicates with a plurality of mobile stations via an array antenna, comprising the steps of:

receiving, using said array antenna, a plurality of uplink signals transmitted from said plurality of mobile stations;

providing a downlink array weight for transmitting downlink signals to one of said plurality of mobile stations such that said downlink array weight represents an antenna pattern having a maximum beam in a direction of said one of the plurality of mobile stations which transmitted a first uplink signal received using said array antenna, and having a null in a direction of a mobile station other than said one of the plurality of mobile stations which transmitted a second uplink signal received using said array antenna,

wherein said downlink array weight is provided according to transmission power control information for a plurality of downlinks to said plurality of mobile stations.

2. The transmission control method according to claim 1, wherein said transmission power control information is used to select said mobile station other than said one of the plurality of mobile stations for which said antenna pattern has a null.

3. The transmission control method according to claim 1, wherein said transmission power control information is determined according to a transmission rate for a corresponding downlink.

4. The transmission control method according to claim 1, wherein the direction for the maximum beam is determined according to spatial information extracted from a plurality of symbols of the first uplink signal, and the direction for the null is determined according to spatial information extracted from a plurality of symbols of the second uplink signal.