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US 8,897,393 B1Granted
Protected codebook selection at receiver for transmit beamforming
AssigneeMarvell International Ltd.
InventorsHongyuan Zhang, Rohit U. Nabar, Atul Salhotra
Life of this patent
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Abstract
In one or more embodiments, in a communications terminal an estimated channel matrix is constructed based on a codebook. A modified estimated channel matrix is calculated based on both the estimated channel matrix and a protection matrix, and a channel submatrix is selected from the modified estimated channel matrix. A selection matrix is calculated from the channel submatrix, and fed back to be used in generating a steering matrix.
Claims33
A method implemented in a communications terminal, the method comprising:
- performing a sounding on a channel using a codebook to produce a channel sounding spatial matrix;
- constructing an estimated channel matrix based on the channel sounding;
- selecting multiple elements of a protection matrix, the selecting the multiple elements effective to prevent generating a steering matrix that shuts down one or more antennas of a transmitter if the channel sounding spatial matrix is an identity matrix;
- calculating a modified estimated channel matrix by multiplying the estimated channel matrix and the protection matrix;
- selecting a channel submatrix from the modified estimated channel matrix;
- calculating a selection matrix from the channel submatrix;
- and
- feeding back the selection matrix to be used in generating the steering matrix.
5 more elements
A communications terminal comprising:
- a channel matrix estimation unit to construct an estimated channel matrix based on a channel sounding, a codebook being used to produce a channel sounding spatial matrix to perform the channel sounding;
- a modified channel matrix estimation unit to calculate a modified estimated channel matrix by multiplying the estimated channel matrix and a protection matrix, the protection matrix comprising multiple elements selected to prevent generating a steering matrix that shuts down one or more antennas of a transmitter if the channel sounding spatial matrix is an identity matrix;
- a channel submatrix selection unit to select a channel submatrix from the modified estimated channel matrix;
- a selection matrix calculator to calculate a selection matrix from the channel submatrix;
- and
- a feedback unit to feed back the selection matrix to be used in generating the steering matrix.
3 more elements
Dependencies are inferred from the claim text.