Feedback control method and apparatus in closed-loop transmit diversity
First Claim
1. A feedback control method in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio-base station, comprising:
- receiving downlink pilot signals, which are transmitted by a handover-destination base station, during handover control;
calculating feedback information, which represents amount of phase control transmitted to said handover-destination base station, beforehand based upon the pilot signals received; and
transmitting said feedback information to the handover-destination base station before completion of base-station changeover by handover.
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Accused Products
Abstract
Disclosed is a feedback control method in closed-loop transmit diversity in which feedback information representing amounts of amplitude and phase control is transmitted from a mobile station to a radio base station. The mobile station receives downlink pilot signals, which are transmitted by a handover-destination base station, during handover control, calculates feedback information, which represents amounts of amplitude and phase and phase control transmitted to the handover-destination base station, beforehand based upon the pilot signals received, and transmits the feedback information to the handover-destination base station before completion of base-station changeover by handover.
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Citations
11 Claims
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1. A feedback control method in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio-base station, comprising:
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receiving downlink pilot signals, which are transmitted by a handover-destination base station, during handover control;
calculating feedback information, which represents amount of phase control transmitted to said handover-destination base station, beforehand based upon the pilot signals received; and
transmitting said feedback information to the handover-destination base station before completion of base-station changeover by handover. - View Dependent Claims (2, 3, 4)
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5. A feedback control method in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio base station, comprising:
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receiving each of downlink pilot signals, which are transmitted by a plurality of base stations, during soft handover control;
calculating feedback information, which represents amount of phase control transmitted to each base station, based upon each of the pilot signals received; and
transmitting said feedback information to a handover-destination base station before completion of base-station changeover by soft handover. - View Dependent Claims (6, 7)
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8. A feedback control method in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio base station, comprising:
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receiving each of downlink pilot signals, which are transmitted by a plurality of base stations, during soft handover control;
calculating feedback information, which represents amount of phase control transmitted to each base station, based upon each of the pilot signals received, and calculating receive power from each base station based upon received pilot signals;
deciding that a base station exhibiting maximum receive power is a changeover-destination base station; and
transmitting an ID of said changeover-destination base station and the feedback information, which is sent to said changeover-destination base station, to the base stations simultaneously.
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9. A feedback apparatus of a mobile station in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio base station, said feedback apparatus comprising:
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a receiver for receiving downlink pilot signals, which are transmitted by a handover-destination base station during handover control;
a control-amount calculation unit for calculating feedback information, which represents amount of phase control transmitted to the handover-destination base station, beforehand based upon the pilot signals received; and
a transmitter for transmitting said feedback information to the handover-destination base station before completion of base-station changeover by handover.
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10. A feedback apparatus of a mobile station in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio base station, said feedback apparatus comprising:
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a receiver for receiving each of downlink pilot signals, which are transmitted by a plurality of base stations, during soft handover control;
a control-amount calculation unit for calculating feedback information, which represents amount of phase control transmitted to each base station, based upon each of the pilot signals received; and
a transmitter for transmitting said feedback information to a handover-destination base station before completion of base-station changeover by soft handover.
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11. A feedback apparatus of a mobile station in closed-loop transmit diversity in which feedback information representing at least an amount of phase control is transmitted from a mobile station to a radio base station, said feedback apparatus comprising:
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a receiver for receiving each of downlink pilot signals, which are transmitted by a plurality of base stations, during soft handover control;
a control-amount calculation unit for calculating feedback information, which represents amount of phase control transmitted to each base station, based upon each of the pilot signals received;
a receive-power calculation unit for calculating receive power from each base station based upon received pilot signals;
a changeover-destination base station decision unit for deciding that a base station exhibiting maximum receive power is a changeover-destination base station; and
a transmitter for transmitting an ID of said changeover-destination base station and the feedback information, which is sent to said changeover-destination base station, to the base stations simultaneously.
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Specification