Noise variance estimation in wireless communications for diversity combining and log-likelihood scaling
First Claim
Patent Images
1. A method of estimating noise variance, comprising:
- receiving a signal including an Orthogonal Frequency Division Multiplexing (OFDM) symbol having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones;
estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones; and
estimating an effective noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones.
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Abstract
Noise variance estimation in wireless communications. Noise variance estimation includes receiving a signal including an OFDM symbol having, in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones, and estimating an effective noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones.
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Citations
74 Claims
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1. A method of estimating noise variance, comprising:
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receiving a signal including an Orthogonal Frequency Division Multiplexing (OFDM) symbol having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones; and estimating an effective noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of estimating noise variance, comprising:
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receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; estimating an effective noise variance for the in-band tones of one of the OFDM symbols by estimating a noise variance for the in-band tones of one or more of the OFDM symbols, weighting the noise variance estimates, combining the weighted noise variance estimates, and scaling the combined weighted noise variance estimates; and estimating an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of estimating noise variance, comprising:
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receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; estimating an effective noise variance for the in-band tones of one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and channel estimates for said one of the OFDM symbols, the channel estimates being time averaged over two or more of the OFDM symbols; and estimating an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method of estimating noise variance, comprising:
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receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OPDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; estimating an effective noise variance for the in-band tones of one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and channel estimates for said one of the OFDM symbols; and estimating an effective noise variance for the band-edge tones of said one of the OFDM symbols by estimating an average effective noise variance for the band-edge tones from the band-edge pilot tones for said one of the OFDM symbols, the channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols, assigning the edge tones of the OFDM symbol to an effective noise variance equal to the maximum of the average effective noise variance for the band-edge tones and the effective noise variance for the in-band tones, and interpolating the effective noise variance for the band- edge tones between the effective noise variance of the edge tones and the effective noise variance of the in-band tones. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A demodulator configured to receive a signal including an Orthogonal Frequency Division Multiplexing (OFDM) symbol having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, the demodulator comprising:
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a channel estimator configured to generate channel estimates for the in-band pilot tones and channel estimates for the band-edge pilot tones; an in-band estimator configured to estimate an effective noise variance for the in-band tones using the in-band pilot tones and the channel estimates for the in-band pilot tones; and a band-edge estimator configured to estimate an effective noise variance for the band-edge tones using the band-edge pilot tones, the channel estimates for the band-edge pilot tones, and the guard tones. - View Dependent Claims (26, 27, 28, 29, 30)
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31. A demodulator configured to receive a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, the demodulator comprising:
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a channel estimator configured to generate channel estimates for the band-edge pilot tones of one of the OFDM symbols; an in-band estimator configured to estimate an effective noise variance for the in-band tones of said one of the OFDM symbols by estimating a noise variance for the in-band tones of one or more of the OFDM symbols, weighting the noise variance estimates, combining the weighted noise variance estimates, and scaling the combined weighted noise variance estimates; and a band-edge estimator configured to estimate an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (32, 33, 34, 35, 36)
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37. A demodulator configured to receive a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, the demodulator comprising:
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a channel estimator configured to generate channel estimates for the in-band pilot tones of one of the OFDM symbols and channel estimates for the band-edge pilot tones of said one of the OFDM symbols, the channel estimates for the in-band pilot tones for said one of the OFDM symbols being time averaged over two or more of the OFDM symbols; an in-band estimator configured to estimate an effective noise variance for the in-band tones of said one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and the channel estimates for said one of the OFDM symbols; and a band-edge estimator configured to estimate an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, the channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (38, 39, 40, 41, 42)
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43. A demodulator configured to receive a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, the demodulator comprising:
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a channel estimator configured to generate channel estimates for the in-band pilot tones of one of the OFDM symbols and channel estimates for the band-edge pilot tones of said one of the OFDM symbols; an in-band estimator configured to estimate an effective noise variance for the in-band tones of said one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and channel estimates for said one of the OFDM symbols; and a band-edge estimator configured to estimate an effective noise variance for the band-edge tones of said one of the OFDM symbols by estimating an average effective noise variance for the band-edge tones for said one of the OFDM symbols from the band-edge pilot tones for said one of the OFDM symbols, the channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols, assigning the edge tones of the OFDM symbol to an effective noise variance equal to the maximum of the average effective noise variance for the band-edge tones for said one of the OFDM symbols and the effective noise variance for the in-band tones for said one of the OFDM symbols, and interpolating the effective noise variance for the band-edge tones between the effective noise variance of the edge tones and the effective noise variance of the in-band tones. - View Dependent Claims (44, 45, 46, 47, 48)
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49. A wireless communication apparatus adapted to receive signals from a plurality of antennas, including signals having an Orthogonal Frequency Division Multiplex (OFDM) symbol with in-band pilot tones, band-edge pilot tones, and guard tones, the apparatus comprising:
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a channel estimator to generate channel estimates for the in-band pilot tones and band-edge pilot tones; an in-band channel estimator to estimate an effective noise variance of the in-band tones using the in-band pilot tones and the channel estimates for the in-band pilot tones; a band-edge estimator to estimate an effective noise variance for the band-edge tones using the band-edge pilot tones and the channel estimates for the band-edge tones; and a controller for evaluating reliability of the plurality of antennas. - View Dependent Claims (50)
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51. An apparatus for estimating noise variance, comprising:
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means for receiving a signal including an Orthogonal Frequency Division Multiplexing (OFDM) symbol having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; means for estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones; and means for estimating an effective noise variance for the band-edge tones using the band- edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones. - View Dependent Claims (52, 53, 54, 55, 56)
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57. An apparatus for estimating noise variance, comprising:
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means for receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; means for estimating an effective noise variance for the in-band tones of one of the OFDM symbols by estimating a noise variance for the in-band tones of one or more of the OFDM symbols, weighting the noise variance estimates, combining the weighted noise variance estimates, and scaling the combined weighted noise variance estimates; and means for estimating an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (58, 59, 60, 61, 62)
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63. An apparatus for estimating noise variance, comprising:
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means for receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; means for estimating an effective noise variance for the in-band tones of one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and channel estimates for said one of the OFDM symbols, the channel estimates being time averaged over two or more of the OFDM symbols; and means for estimating an effective noise variance for the band-edge tones of said one of the OFDM symbols using the band-edge pilot tones for said one of the OFDM symbols, channel estimates for the band-edge pilot tones for said one of the OPDM symbols, and the guard tones for said one of the OFDM symbols. - View Dependent Claims (64, 65, 66, 67, 68)
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69. An apparatus for estimating noise variance, comprising:
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means for receiving a signal including a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols each having in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones; means for estimating an effective noise variance for the in-band tones of one of the OFDM symbols using the in-band pilot tones for said one of the OFDM symbols and channel estimates for said one of the OFDM symbols; and means for estimating an effective noise variance for the band-edge tones of said one of the OFOM symbols by estimating an average effective noise variance for the band-edge tones from the band-edge pilot tones for said one of the OFDM symbols, the channel estimates for the band-edge pilot tones for said one of the OFDM symbols, and the guard tones for said one of the OFDM symbols, assigning the edge tones of the OFDM symbol to an effective noise variance equal to the maximum of the average effective noise variance for the band-edge tones and the effective noise variance for the in-band tones, and interpolating the effective noise variance for the band-edge tones between the effective noise variance of the edge tones and the effective noise variance of the in-band tones. - View Dependent Claims (70, 71, 72, 73, 74)
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Specification