Derivation and feedback of transmit steering matrix
First Claim
1. An apparatus comprising:
- at least one processor configured to determine a set of parameters defining a set of transformation matrices for deriving a transmit steering matrix to be used for transmission from a transmitter using multiple transmit antennas to a receiver using multiple receive antennas, wherein the transmit steering matrix is representable as a product of the transformation matrices, and send the set of parameters to the transmitter for use by the transmitter to derive the transmit steering matrix;
a memory coupled to the at least one processor, andwherein the at least one processor is configured to perform a plurality of iterations of Jacobi rotation on a channel matrix which is derived based on a channel response estimate with the plurality of transformation matrices to zero out off-diagonal elements of the channel matrix,wherein for each iteration of the Jacobi rotation the at least one processor is configured to derive a transformation matrix as an identity matrix having diagonal and off-diagonal elements replaced with elements derived from eigenvectors of the channel matrix, to update the transmit steering matrix based on the transformation matrix to zero out off-diagonal elements of the channel matrix,identify a largest off-diagonal element of the channel matrix, and to derive the transformation matrix based on row and column indices of the largest off-diagonal element.
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Abstract
Techniques for efficiently deriving a transmit steering matrix and sending feedback for this matrix are described. A receiver determines a set of parameters defining a transmit steering matrix to be used for transmission from a transmitter to the receiver. The receiver may derive the transmit steering matrix based on a set of transformation matrices, which may be used for multiple iterations of Jacobi rotation to zero out off-diagonal elements of a channel matrix. The receiver may then determine the set of parameters based on the transformation matrices. The set of parameters may comprise at least one angle, at least one value, at least one index, etc., for each transformation matrix. The receiver sends the set of parameters defining the transmit steering matrix (instead of elements of the transmit steering matrix) to the transmitter for use by the transmitter to derive the transmit steering matrix.
175 Citations
20 Claims
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1. An apparatus comprising:
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at least one processor configured to determine a set of parameters defining a set of transformation matrices for deriving a transmit steering matrix to be used for transmission from a transmitter using multiple transmit antennas to a receiver using multiple receive antennas, wherein the transmit steering matrix is representable as a product of the transformation matrices, and send the set of parameters to the transmitter for use by the transmitter to derive the transmit steering matrix; a memory coupled to the at least one processor, and wherein the at least one processor is configured to perform a plurality of iterations of Jacobi rotation on a channel matrix which is derived based on a channel response estimate with the plurality of transformation matrices to zero out off-diagonal elements of the channel matrix, wherein for each iteration of the Jacobi rotation the at least one processor is configured to derive a transformation matrix as an identity matrix having diagonal and off-diagonal elements replaced with elements derived from eigenvectors of the channel matrix, to update the transmit steering matrix based on the transformation matrix to zero out off-diagonal elements of the channel matrix, identify a largest off-diagonal element of the channel matrix, and to derive the transformation matrix based on row and column indices of the largest off-diagonal element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method comprising:
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determining a set of parameters defining a set of transformation matrices for deriving a transmit steering matrix to be used for transmission from a transmitter using multiple transmit antennas to a receiver using multiple receive antennas, wherein the transmit steering matrix is representable as a product of the transformation matrices; and sending the set of parameters to the transmitter for use by the transmitter to derive the transmit steering matrix, wherein the determining the set of parameters comprises deriving the transmit steering matrix based on the plurality of transformation matrices, and determining the set of parameters based on the plurality of transformation matrices, wherein the deriving the transmit steering matrix comprises performing a plurality of iterations of Jacobi rotation on a channel matrix which is derived based on a channel response estimate with the plurality of transformation matrices, and for each iteration of the Jacobi rotation, deriving a transformation matrix as an identity matrix having diagonal and off-diagonal elements replaced with elements derived from eigenvectors of the channel matrix, updating the channel matrix based on the transformation matrix, and updating the transmit steering matrix based on the transformation matrix to zero out off-diagonal elements of the channel matrix, identifying a largest off-diagonal element of the channel matrix, and to derive the transformation matrix based on row and column indices of the largest off-diagonal element. - View Dependent Claims (13)
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14. An apparatus comprising:
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means for determining a set of parameters defining a set of transformation matrices for deriving a transmit steering matrix to be used for transmission from a transmitter using multiple transmit antennas to a receiver using multiple receive antennas, wherein the transmit steering matrix is representable as a product of the transformation matrices; and means for sending the set of parameters to the transmitter for use by the transmitter to derive the transmit steering matrix, wherein the means for determining the set of parameters comprises means for deriving the transmit steering matrix based on the plurality of transformation matrices, and means for determining the set of parameters based on the plurality of transformation matrices, wherein the means for deriving the transmit steering matrix comprises means for performing a plurality of iterations of Jacobi rotation on a channel matrix which is derived based on a channel response estimate with the plurality of transformation matrices, and means for, for each iteration of the Jacobi rotation, deriving a transformation matrix as an identity matrix having diagonal and off-diagonal elements replaced with elements derived from eigenvectors of the channel matrix, updating the channel matrix based on the transformation matrix, and updating the transmit steering matrix based on the transformation matrix to zero out off-diagonal elements of the channel matrix, identifying a largest off-diagonal element of the channel matrix, and to derive the transformation matrix based on row and column indices of the largest off-diagonal element. - View Dependent Claims (15)
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16. An apparatus comprising:
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at least one processor configured to receive a set of parameters defining a set of transformation matrices for deriving a transmit steering matrix, wherein the transmit steering matrix is representable as a product of the transformation matrices, to form the set of transformation matrices based on the set of parameters, to derive the transmit steering matrix based on the set of transformation matrices, and to use the transmit steering matrix for transmission from a transmitter using multiple transmit antennas to a receiver using multiple receive antennas; a memory coupled to the at least one processor, and wherein the at least one processor is configured to perform a plurality of iterations of Jacobi rotation on a channel matrix which is derived based on a channel response estimate with the plurality of transformation matrices to zero out off-diagonal elements of the channel matrix, wherein for each iteration of the Jacobi rotation the at least one processor is configured to derive a transformation matrix as an identity matrix having diagonal and off-diagonal elements replaced with elements derived from eigenvectors of the channel matrix, to update the transmit steering matrix based on the transformation matrix to zero out off-diagonal elements of the channel matrix, identify a largest off-diagonal element of the channel matrix, and to derive the transformation matrix based on row and column indices of the largest off-diagonal element. - View Dependent Claims (17, 18, 19, 20)
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Specification