Wireless communications apparatus
First Claim
1. A method of determining a beamforming vector for use in wireless communication involving apparatus comprising a plurality of antennas, each being suitable for emitting a wireless signal, including determining said beamforming vector on the basis of a measure of transmission channel to a given receiver, said measure being expressible in the form of a channel matrix, the determining including determining an eigen-beamformer vector from said channel matrix and, for a number of iterations wherein the initial iteration is performed on a vector being said eigen-beamformer vector,rotating said eigen-beamformer vector into a reference direction in vector space to produce a rotated eigen-beamformer vector whose application would result in peak radiation being directed in said reference direction,sampling a radiation pattern associated with said rotated eigen-beamformer vector with respect to transmission direction,compressing the samples obtained from sampling the radiation pattern to reduce spatial directivity induced by said rotated eigen-beamformer vector,developing a rotated candidate beamformer on the basis of said compressed samples and returning said rotated candidate beamformer to the orientation of said eigen-beamformer vector before said rotating, thereby to produce a resultant vector andstoring said resultant vector as a candidate vector;
- then comparing said candidate vectors for said iterations and selecting that for use which best meets one or more selection criteria.
1 Assignment
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Accused Products
Abstract
Determining a beamforming vector for a multi-antenna transmitter commences by determining an eigen-beamformer vector from the channel matrix and, for a number of iterations commencing with the eigen-beamformer vector, rotating the vector into a reference direction in vector space such that application of the rotated vector would result in peak radiation being directed in said reference direction, sampling a radiation pattern associated with the rotated eigen-beamformer vector with respect to transmission direction, compressing resultant samples to reduce spatial directivity induced by the vector, developing a rotated candidate beamformer on the basis of said compressed samples and returning said rotated candidate beamformer to the orientation of said vector before said rotating and storing said resultant vector as a candidate vector. Then, the candidate vectors are compared for the iterations and one is selected for use which best meets one or more selection criteria.
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Citations
19 Claims
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1. A method of determining a beamforming vector for use in wireless communication involving apparatus comprising a plurality of antennas, each being suitable for emitting a wireless signal, including determining said beamforming vector on the basis of a measure of transmission channel to a given receiver, said measure being expressible in the form of a channel matrix, the determining including determining an eigen-beamformer vector from said channel matrix and, for a number of iterations wherein the initial iteration is performed on a vector being said eigen-beamformer vector,
rotating said eigen-beamformer vector into a reference direction in vector space to produce a rotated eigen-beamformer vector whose application would result in peak radiation being directed in said reference direction, sampling a radiation pattern associated with said rotated eigen-beamformer vector with respect to transmission direction, compressing the samples obtained from sampling the radiation pattern to reduce spatial directivity induced by said rotated eigen-beamformer vector, developing a rotated candidate beamformer on the basis of said compressed samples and returning said rotated candidate beamformer to the orientation of said eigen-beamformer vector before said rotating, thereby to produce a resultant vector and storing said resultant vector as a candidate vector; then comparing said candidate vectors for said iterations and selecting that for use which best meets one or more selection criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 19)
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10. Wireless communications apparatus comprising a plurality of antennas, each antenna being suitable for emitting a wireless signal, and comprising
a beamformer operable to determine a beamforming vector for use in wireless communication involving said apparatus, said beamformer including beamforming vector determining means for determining said beamforming vector on the basis of a measure of transmission channel to a given receiver, said measure being expressible in the form of a channel matrix, the beamforming vector determining means including eigen-beamformer vector determining means for determining an eigen-beamformer vector from said channel matrix and including, operable for a number of iterations wherein the initial iteration is performed on a vector being said eigen-beamformer vector: -
vector rotation means for rotating said eigen-beamformer vector into a reference direction in vector space to produce a rotated eigen-beamformer vector whose application would result in peak radiation being directed in said reference direction, sampling means for sampling a radiation pattern associated with said rotated eigen-beamformer vector with respect to transmission direction, compressing means for compressing samples obtained from sampling the radiation pattern to reduce spatial directivity induced by said rotated eigen-beamformer vector, beamformer developing means for developing a rotated candidate beamformer on the basis of said compressed samples and returning said rotated candidate beamformer to the orientation of said eigen-beamformer vector before said rotating, thereby to produce a resultant vector and vector storing means for storing said resultant vector as a candidate vector; and
result comparison means for comparing said candidate vectors for said iterations and to select that for use which best meets one or more selection criteria. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification