Method and apparatus for transmitting signals in a multi-antenna mobile communications system that compensates for channel variations
First Claim
1. A method of transmitting signals from a transmitter comprising two or more transmit antennas in a mobile telecommunications network, the method comprisingdetermining channel state information,estimating reliability of the channel state information,space time block encoding at least one data sequence,before transmitting the data sequence, applying to the data sequence a linear transformation so as to at least partially compensate for channel variations, the linear transformation being dependent upon the channel state information and dependent upon the estimated reliability of the channel state information,in which where the channel state information is channel estimates in the form of channel coefficients, and the channel state information for a time interval (n) is assumed accurate for the previous time interval (n−
- 1), the channel state information reliability (ρ
) is determined as
ρ
(1)=0
ρ
(n)=(1−
α
)hf*+α
ρ
(n−
1)
where h is the channel vector, f is the latest channel state information, and α
is a forgetting factor.
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Abstract
A method is provided for transmitting signals from a transmitter comprising two or more antennas in a mobile telecommunications network. The method involves determining channel state information, estimating the reliability of that channel state information, and space time block encoding at least one data sequence. Before transmitting the data sequence, a linear transformation is applied to the data sequence so as to at least partially compensate for channel variations. The linear transformation is dependent upon the channel state information and upon the estimated reliability of the channel state information.
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Citations
23 Claims
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1. A method of transmitting signals from a transmitter comprising two or more transmit antennas in a mobile telecommunications network, the method comprising
determining channel state information, estimating reliability of the channel state information, space time block encoding at least one data sequence, before transmitting the data sequence, applying to the data sequence a linear transformation so as to at least partially compensate for channel variations, the linear transformation being dependent upon the channel state information and dependent upon the estimated reliability of the channel state information, in which where the channel state information is channel estimates in the form of channel coefficients, and the channel state information for a time interval (n) is assumed accurate for the previous time interval (n− - 1), the channel state information reliability (ρ
) is determined as
ρ
(1)=0
ρ
(n)=(1−
α
)hf*+α
ρ
(n−
1)
where h is the channel vector, f is the latest channel state information, and α
is a forgetting factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- 1), the channel state information reliability (ρ
-
12. A transmitter for mobile telecommunications comprising at least two transmit antennas, a space tune block encoder, a linear transformation apparatus operative to transform a data sequence from or to a space time block encoder so as to at least partially compensate for channel variations, a processor operative to receive channel state information and to estimate reliability of the channel state information, and a processor operative to determine the linear transformation to be applied dependent upon the channel state information and the estimated reliability of the channel state information,
in which where the channel state information is channel estimates in the form of channel coefficients, and the channel state information for a time interval (n) is assumed accurate for the previous time interval (n− - 1), the channel state information reliability (ρ
) is determined as
ρ
(1)=0
ρ
(n)=(1−
α
)hf*+α
ρ
(n−
1)
where h is the channel vector, f is the latest channel state information, and α
is a forgetting factor. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
- 1), the channel state information reliability (ρ
-
23. A network for mobile telecommunications comprising a transmitter and a receiver,
the transmitter comprising a space-time block encoder and a linear transformation apparatus operative to transform a data sequence from or to the space-time block encoder by applying a linear transformation so as to at least partially compensate for channel variations, the transmitter comprising at least two transmit antennas, the receiver comprising a space-time block decoder and a channel estimator, a processor operative to estimate channel state information reliability from channel state information provided by the channel estimator, and a processor operative to determine the coefficients of a further linear transformation matrix dependent upon the channel state information and the estimated reliability of the channel state information to be applied to a further data sequence for transmission, the coefficients of the further linear transformation matrix being sent from the receiver to the transmitter for use.
Specification
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- Resources
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Current AssigneeRPX Corporation
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Original AssigneeLucent Technologies, Inc. (Nokia Corporation)
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InventorsAlexiou, Angeliki, Qaddi, Mohammed
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Primary Examiner(s)TRAN, KHANH C
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Application NumberUS10/620,987Publication NumberTime in Patent Office1,455 DaysField of Search375259-260, 375/267, 375/295, 375/358, 375/299, 375/347, 370329-330, 370/332, 370/350, 455500-506, 455/63.1, 455/65, 455/101, 455/562.1, 455/115.1US Class Current375/267CPC Class CodesH04B 7/0626 Channel coefficients, e.g. ...H04B 7/0656 at the transmitter, e.g. er...H04B 7/0669 using different channel cod...H04L 1/0618 Space-time codingH04L 25/0202 Channel estimationH04L 25/0248 Eigen-space methods
