Channel estimation and spatial processing for TDD MIMO systems
First Claim
1. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
- processing a first transmission received via a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link; and
performing spatial processing for a second transmission with the at least one eigenvector prior to transmission over the second link.
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Accused Products
Abstract
Channel estimation and spatial processing for a TDD MIMO system. Calibration may be performed to account for differences in the responses of transmit/receive chains at the access point and user terminal. During normal operation, a MIMO pilot is transmitted on a first link and used to derive an estimate of the first link channel response, which is decomposed to obtain a diagonal matrix of singular values and a first unitary matrix containing both left eigenvectors of the first link and right eigenvectors of a second link. A steered reference is transmitted on the second link using the eigenvectors in the first unitary matrix, and is processed to obtain the diagonal matrix and a second unitary matrix containing both left eigenvectors of the second link and right eigenvectors of the first link. Each unitary matrix may be used to perform spatial processing for data transmission/reception via both links.
91 Citations
59 Claims
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1. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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processing a first transmission received via a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link; and
performing spatial processing for a second transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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means for processing a first transmission received via a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link; and
means for performing spatial processing for a second transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (15, 16, 17, 18)
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19. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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a controller operative to process a first transmission received via a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link; and
a transmit spatial processor operative to perform spatial processing for a second transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (20, 21, 22, 23)
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24. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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processing a MIMO pilot received via a first link to obtain a plurality of eigenvectors usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link, wherein the MIMO pilot comprises a plurality of pilot transmissions sent from a plurality of transmit antennas, and wherein the pilot transmission from each transmit antenna is identifiable by a receiver of the MIMO pilot;
performing spatial processing on a first data transmission received via the first link with the plurality of eigenvectors to recover data symbols for the first data transmission; and
performing spatial processing for a second data transmission with the plurality of eigenvectors prior to transmission over the second link. - View Dependent Claims (25, 26, 27)
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28. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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means for processing a MIMO pilot received via a first link to obtain a plurality of eigenvectors usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link, wherein the MIMO pilot comprises a plurality of pilot transmissions sent from a plurality of transmit antennas, and wherein the pilot transmission from each transmit antenna is identifiable by a receiver of the MIMO pilot;
means for performing spatial processing on a first data transmission received via the first link with the plurality of eigenvectors to recover data symbols for the first data transmission; and
means for performing spatial processing for a second data transmission with the plurality of eigenvectors prior to transmission over the second link. - View Dependent Claims (29, 30)
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31. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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a controller operative to process a MIMO pilot received via a first link to obtain a plurality of eigenvectors usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link, wherein the MIMO pilot comprises a plurality of pilot transmissions sent from a plurality of transmit antennas, and wherein the pilot transmission from each transmit antenna is identifiable by a receiver of the MIMO pilot;
a receive spatial processing operative to perform spatial processing on a first data transmission received via the first link with the plurality of eigenvectors to recover data symbols for the first data transmission; and
a transmit spatial processor operative to perform spatial processing for a second data transmission with the plurality of eigenvectors prior to transmission over the second link - View Dependent Claims (32, 33)
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34. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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processing a steered pilot received via at least one eigenmode of a MIMO channel for a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link;
performing spatial processing on a first data transmission received via the first link with the at least one eigenvector; and
performing spatial processing for a second data transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (35)
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36. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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means for processing a steered pilot received via at least one eigenmode of a MIMO channel for a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link;
means for performing spatial processing on a first data transmission received via the first link with the at least one eigenvector; and
means for performing spatial processing for a second data transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (37)
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38. An apparatus in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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a controller operative to process a steered pilot received via at least one eigenmode of a MIMO channel for a first link to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link;
a receive spatial processor operative to perform spatial processing on a first data transmission received via the first link with the at least one eigenvector; and
a transmit spatial processor operative to perform spatial processing for a second data transmission with the at least one eigenvector prior to transmission over the second link. - View Dependent Claims (39)
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40. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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performing spatial processing on pilot symbols with a normalized eigenvector for one eigenmode of a MIMO channel to generate a first steered pilot for transmission via the one eigenmode of the MIMO channel, the normalized eigenvector including a plurality of elements having same magnitude; and
performing spatial processing on data symbols with the normalized eigenvector prior to transmission on the one eigenmode of the MIMO channel. - View Dependent Claims (41)
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42. A method of performing spatial processing in a wireless time division duplexed (TDD) multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication system, comprising:
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processing a first transmission received via a first link to obtain a matrix of eigenvectors for each of a plurality of subbands, wherein a plurality of matrices of eigenvectors are obtained for the plurality of subbands and are usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link; and
performing spatial processing for a second transmission with the plurality of matrices of eigenvectors prior to transmission over the second link. - View Dependent Claims (43, 44)
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45. A method of estimating a wireless channel in a time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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processing a pilot transmission received via a first link to obtain a channel response estimate for the first link; and
decomposing the channel response estimate to obtain a matrix of eigenvectors usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link.
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46. A method of estimating a wireless channel in a time division duplexed (TDD) multiple-input multiple-output (MIMO) communication system, comprising:
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receiving a steered pilot on at least one eigenmode of a MIMO channel for a first link; and
processing the received steered pilot to obtain at least one eigenvector usable for spatial processing for both data transmission received via the first link and data transmission sent via a second link. - View Dependent Claims (47, 48, 49)
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50. A method for performing data processing in a wireless communication system including an access point and a user terminal, the method comprising:
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calibrating one or more communication links including a first link and a second link between the access point and the user terminal to form a calibrated first link and a calibrated second link;
obtaining a channel response estimate for the calibrated first link based on one or more pilots transmitted on the calibrated first link; and
decomposing the channel response estimate to obtain one or more eigenvectors usable for spatial processing of the one or more communication links. - View Dependent Claims (51, 52, 53, 54)
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55. An apparatus for performing data processing in a wireless communication system including an access point and a user terminal, the apparatus comprising:
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means for calibrating one or more communication links including a first link and a second link between the access point and the user terminal to form a calibrated first link and a calibrated second link;
means for obtaining a channel response estimate for the calibrated first link based on one or more pilots transmitted on the calibrated first link; and
means for decomposing the channel response estimate to obtain one or more eigenvectors usable for spatial processing of the one or more communication links. - View Dependent Claims (56, 57, 58, 59)
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Specification