Adaptive transmit antenna diversity apparatus and method in a mobile communication system
First Claim
1. An apparatus for selecting one of an open-loop first transmit antenna diversity scheme and closed-loop second transmit antenna diversity schemes by a user equipment (UE) in a system including a Node B transmitter which includes at least two antennas and uses the first transmit antenna diversity scheme for transmitting space time transmit diversity (STTD)-encoded signals via the antennas and the second transmit antenna diversity scheme for controlling a phase of signals transmitted from the antennas in response to feedback information including relative phase difference information of the antennas from the UE, the apparatus comprising:
- a channel estimator for receiving a first channel signal from the Node B transmitter, and estimating a channel response from the received first channel signal;
a determiner for estimating a variation speed of the first channel based on the estimated channel response, and selecting one of the first and second transmit antenna diversity schemes according to the estimated variation speed of the first channel; and
an information generator for generating information indicating the selected transmit antenna diversity scheme.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus and method are disclosed for selecting a transmit antenna diversity scheme according to a variation speed of a fading channel in a mobile communication system. A user equipment (UE) estimates a channel response of a pilot channel by receiving a pilot channel signal from a Node B; estimates a variation speed of a fading channel by using the estimated channel response and determining a transmit antenna diversity scheme suitable to the variation speed of the fading channel; and transmits feedback information including the determined transmit antenna diversity scheme to the Node B, so that the Node B can determine a transmit antenna diversity scheme for a channel signal to be transmitted to the UE based on the transmit antenna diversity scheme information included in the feedback information. In this way, the Node B adaptively applies a transmit antenna diversity according to a channel condition.
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Citations
16 Claims
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1. An apparatus for selecting one of an open-loop first transmit antenna diversity scheme and closed-loop second transmit antenna diversity schemes by a user equipment (UE) in a system including a Node B transmitter which includes at least two antennas and uses the first transmit antenna diversity scheme for transmitting space time transmit diversity (STTD)-encoded signals via the antennas and the second transmit antenna diversity scheme for controlling a phase of signals transmitted from the antennas in response to feedback information including relative phase difference information of the antennas from the UE, the apparatus comprising:
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a channel estimator for receiving a first channel signal from the Node B transmitter, and estimating a channel response from the received first channel signal; a determiner for estimating a variation speed of the first channel based on the estimated channel response, and selecting one of the first and second transmit antenna diversity schemes according to the estimated variation speed of the first channel; and an information generator for generating information indicating the selected transmit antenna diversity scheme. - View Dependent Claims (2, 3, 4)
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5. An apparatus for selecting, by a Node B, an open-loop first transmit antenna diversity scheme and closed-loop second transmit antenna diversity scheme and transmitting a channel signal according to the selected transmit antenna diversity scheme in a system, the apparatus comprising:
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a Node B which includes at least two antennas and uses the first transmit antenna diversity scheme for transmitting space time transmit diversity (STTD)-encoded signals via the antennas and the second transmit antenna diversity scheme for controlling a phase of signals transmitted from the antennas in response to feedback information including relative phase difference information of the antennas from a user equipment (UE); an information extractor for receiving a first channel signal from the UE, and detecting, from the received first channel signal, information indicating one of the first and second transmit antenna diversity schemes, selected by the UE; a controller for determining a transmit antenna diversity scheme to be applied to channel signals to be transmitted by the Node B, based on the detected information; and a transmitter for encoding the channel signals according to the determined transmit antenna diversity scheme and transmitting the encoded channel signals. - View Dependent Claims (6, 7, 8)
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9. A method for selecting one of an open-loop first transmit antenna diversity scheme and closed-loop second transmit antenna diversity scheme by a user equipment (UE) in a system including a Node B transmitter which includes at least two antennas and uses the first transmit antenna diversity scheme for transmitting space time transmit diversity (STTD)-encoded signals via the antennas and the second transmit antenna diversity scheme for controlling a phase of signals transmitted from the antennas in response to feedback information including relative phase difference information of the antennas from the UE, the method comprising the steps of:
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receiving a first channel signal from the Node B transmitter; estimating a channel response from the received first channel signal; estimating a variation speed of the first channel based on the estimated channel response; selecting one of the first and second transmit antenna diversity schemes according to the estimated variation speed of the first channel; and transmitting information indicating the selected transmit antenna diversity scheme to the Node B transmitter. - View Dependent Claims (10, 11, 12)
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13. A method for selecting, by a Node B, one of an open-loop first transmit antenna diversity scheme and closed-loop second transmit antenna diversity scheme and transmitting a channel signal according to the selected transmit antenna diversity scheme in a system, the method comprising the steps of:
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receiving a first channel signal from the User Equipment (UE); detecting, from the received first channel signal, information indicating one of the first and second transmit antenna diversity schemes, selected by the UE, wherein the first transmit antenna diversity scheme is used for transmitting space time transmit diversity (STTD)-encoded signals via the antennas and the second transmit antenna diversity scheme is used for controlling a phase of signals transmitted from the antennas in response to feedback information including relative phase difference information of the antennas from a user equipment (UE); determining a transmit antenna diversity scheme to be applied to channel signals to be transmitted by the Node B, based on the detected information; and encoding the channel signals according to the determined transmit antenna diversity scheme and transmitting the encoded channel signals. - View Dependent Claims (14, 15, 16)
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Specification