Method and apparatus providing low complexity equalization and interference suppression for SAIC GSM/EDGE receiver
First Claim
1. A radio frequency (RF) receiver, comprising baseband means for performing Minimum Mean-Square Error (MMSE) optimization for substantially simultaneously suppressing inter-symbol interference (ISI) and co-channel interference (CCI) on a signal stream comprising real and imaginary signal components.
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Accused Products
Abstract
Disclosed is a RF receiver that includes baseband circuitry for performing Minimum Mean-Square Error (MMSE) optimization for substantially simultaneously suppressing inter-symbol interference (ISI) and co-channel interference (CCI) on a signal stream that comprises real and imaginary signal components. In a preferred embodiment the receiver includes a single receive antenna, and operates as a single/multi antenna interference cancellation (SAIC) receiver. The baseband circuitry operates to determine a set of In-Phase and Quadrature Phase (I-Q) MMSE vector weights that are used to perform the ISI suppression and the CCI suppression. A method for operating the receiver is also disclosed.
49 Citations
43 Claims
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1. A radio frequency (RF) receiver, comprising baseband means for performing Minimum Mean-Square Error (MMSE) optimization for substantially simultaneously suppressing inter-symbol interference (ISI) and co-channel interference (CCI) on a signal stream comprising real and imaginary signal components.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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2. A RF receiver as in claim 1, where said receiver comprises a single receive antenna, and operates as a single/multi antenna interference cancellation (SAIC) receiver.
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3. A RF receiver as in claim 1, where said baseband means comprises means for determining a set of In-Phase and Quadrature Phase (I-Q) MMSE vector weights that are used to perform the ISI suppression and the CCI suppression.
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4. A RF receiver as in claim 3, where signal interference correlation matrices are utilized when calculating I-Q MMSE coefficients, and where the vector weights are synthesized using FIR calculations.
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5. A RF receiver as in claim 3, where signal interference correlation matrices are utilized when calculating I-Q MMSE coefficients, and where the vector weights are synthesized using frequency domain calculations.
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6. A RF receiver as in claim 5, where the frequency domain calculations comprise Fast Fourier Transform (FFT) calculations.
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7. A RF receiver as in claim 1, where said baseband means comprises a multiplier for multiplying the set of determined I-Q MMSE weight vectors with a received signal vector, and said RF receiver further comprises decision means, coupled to an output of said baseband means, for making bit soft decisions on the signal output from said baseband means.
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8. A RF receiver as in claim 7, where said decision means comprises a reduced state sequence estimator (RSSE).
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9. A RF receiver as in claim 7, where said decision means comprises a trellis detector that uses Euclidian metrics.
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10. A RF receiver as in claim 7, where said decision means comprises a trellis detector that uses Ungerboeck metrics.
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11. A RF receiver as in claim 1, where said baseband means comprises a multiplier for multiplying the set of determined I-Q MMSE weight vectors with a received signal vector, and outputs bit soft decisions based on the result of the multiplication.
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12. A RF receiver as in claim 1, where said baseband outputs samples y(k) of the received signal represented as,
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p = 0 v x k - p ( 1 ) h p , q ( 1 ) + ∑ j = 2 M ∑ p = 0 v x k - p ( j ) h l , q ( j ) + n k , q , q = 1 , 2 … l .
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13. A RF receiver as in claim 12, where the real and imaginary parts of the time domain received signal are stacked in a column vector, and the received signal in the frequency-domain is represented as,
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( f ) = h 1 ( f ) x 1 ( f ) + ∑ j = 2 M h j ( f ) x j ( f ) + n ( f ) ,
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14. A RF receiver as in claim 13, where an MMSE filter w(f) that minimizes the mean square error term defined as,
MSE=o∫- E└
∥
w(f)y(f)−
x1(f)∥
2┘
df.
- E└
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15. A RF receiver as in claim 14, where the MMSE weights in direct form are given by,
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( f ) = h 1 * ( f ) ︸ 1 - QMF [ R SS ( f ) + R ii ( f ) ] - 1 ︸ 1 - Q MMSE For Colored Noise .
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16. A RF receiver as in claim 12, where for an I-Q whitened matched filter embodiment the MMSE receiver is represented as,
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( f ) = 1 [ 1 + h 1 * ( f ) R ii - 1 ( f ) h 1 ( f ) ] ︸ Scalar 1 - Q MMSE Equalizer for White Noise h 1 * ( f ) R ii - 1 ( f ) ︸ I - Q WhitenedMF .
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17. A RF receiver as in claim 3, where for an I-Q pre-whitening embodiment the MMSE weights are arranged as,
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( f ) = h ~ 1 * ( f ) ︸ I - Q MF [ 1 + h ~ 1 * ( f ) h ~ 1 ( f ) ] ︸ Scalar - I - Q MMSE Equalizer for White Noise L ii - 1 ( f ) ︸ I - Q Pre - whitener , h ~ 1 ( f ) = L ii - 1 ( f ) h 1 ( f ) .
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18. A RF receiver as in claim 3, where said baseband means operates as a frequency domain I-Q pre-whitener that uses a matrix that is synthesized based on an I-Q interference correlation matrix.
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19. A RF receiver as in claim 3, where said baseband means operates as a frequency domain I-Q whitened matched filter that uses a matrix that is synthesized based on an I-Q interference correlation matrix.
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20. A RF receiver as in claim 3, where said baseband means operates as a frequency domain I-Q pre-whitener that uses a matrix that is synthesized based on an I-Q interference correlation matrix and that outputs pre-whitened signal stream, said RF receiver further comprising a sequence estimator that processes said pre-whitened signal stream with combined I-Q branches within a branch metric, using one of Euclidian and Ungerboeck metrics.
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21. A RF receiver as in claim 3, where said baseband means operates as a frequency domain I-Q whitener matched filter that uses a matrix that is synthesized based on an I-Q interference correlation matrix and that outputs a whitened signal stream, said RF receiver further comprising a sequence estimator that processes said whitened signal stream with combined I-Q branches within a branch metric, using one of Euclidian and Ungerboeck metrics.
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22. A RF receiver as in claim 3, where said baseband means operates as an I-Q MMSE Decision Feedback Equalizer (DFE) pre-filter that outputs a pre-filtered signal stream, said RF receiver further comprising a reduced state sequence estimator (RSSE) that processes said pre-filtered signal stream.
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23. A RF receiver as in claim 1, where a frequency domain form of the I-Q MMSE-DFE is represented as one of,
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( f ) = [ 1 + b ( f ) ] h 1 * ( f ) R ii - 1 ( f ) [ 1 + h 1 * ( f ) R ii - 1 ( f ) h 1 ( f ) ] , and where [1+b(f)] is a feedback filter.
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24. A RF receiver as in claim 1, where for a FIR solution in an exact form, Nf samples are stacked in a column vector as:
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and real and imaginary parts of the samples are stacked as,
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25. A RF receiver as in claim 24, where a 1×
- 2lNf row vector w that minimizes the mean square error between zk=wYk and xk−
Δ
is given by,
w=1Δ
*H1*└
H1H1*+Rii−
1┘
,where 1Δ
is a (Nf+v) vector of 0'"'"'s with a 1 in the Δ
+1 st position, and where Δ
is an equalizer delay that is one of variable or that is selected asfor feed-forward filters of length Nf.
- 2lNf row vector w that minimizes the mean square error between zk=wYk and xk−
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26. A RF receiver as in claim 24, where a feed-forward filter is represented using a matrix inversion formula as,
w=1Δ-
*H1*[H1*Rii−
1H1+I]−
1H1*Rii−
1.
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*H1*[H1*Rii−
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27. A RF receiver as in claim 1, where MMSE-DFE feed-forward and feedback filters in FIR form are given by,
w=1Δ-
*H1*[H1H1*−
H1JΔ
JΔ
*H1*+Rii]−
1,
and
b=1Δ
*H1*[H1H1*−
H1JΔ
JΔ
*H1*+Rii]−
1H1JΔ
,where JΔ
=E[Ykx*k−
Δ
−
1*].
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*H1*[H1H1*−
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2. A RF receiver as in claim 1, where said receiver comprises a single receive antenna, and operates as a single/multi antenna interference cancellation (SAIC) receiver.
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28. A method to operate a radio frequency (RF) receiver, comprising:
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receiving a signal comprising real and imaginary signal components; and
performing Minimum Mean-Square Error (MMSE) optimization on said received signal for substantially simultaneously suppressing inter-symbol interference (ISI) and co-channel interference (CCI). - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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29. A method as in claim 28, where said signal is received through a single receive antenna, and said RF receiver operates as a single/multi antenna interference cancellation (SAIC) receiver.
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30. A method as in claim 28, where performing MMSE optimization comprises determining a set of In-Phase and Quadrature Phase (I-Q) MMSE vector weights that are used to perform the ISI suppression and the CCI suppression.
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31. A method as in claim 30, further comprising using signal interference correlation matrices when calculating I-Q MMSE coefficients, and synthesizing the vector weights using FIR calculations.
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32. A method as in claim 30, further comprising using signal interference correlation matrices when calculating I-Q MMSE coefficients, and synthesizing the vector weights using frequency domain calculations.
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33. A method as in claim 32, where the frequency domain calculations comprise Fast Fourier Transform (FFT) calculations.
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34. A method as in claim 28, where performing MMSE optimization comprises multiplying the set of determined I-Q MMSE weight vectors with a received signal vector to generate a result signal, and further comprising making bit soft decisions on the result signal.
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35. A method as in claim 34, where making bit soft decisions uses a reduced state sequence estimator (RSSE).
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36. A method as in claim 34, where making bit soft decisions uses a trellis detector that uses Euclidian metrics.
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37. A method as in claim 34, where making bit soft decisions uses a trellis detector that uses Ungerboeck metrics.
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38. A method as in claim 28, where performing MMSE optimization comprises multiplying the set of determined I-Q MMSE weight vectors with a received signal vector, and outputting bit soft decisions based on the result of the multiplication.
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39. A method as in claim 30, where performing MMSE optimization comprises operating a frequency domain I-Q pre-whitener that uses a matrix that is synthesized based on an I-Q interference correlation matrix.
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40. A method as in claim 30, where performing MMSE optimization comprises operating a frequency domain I-Q whitened matched filter that uses a matrix that is synthesized based on an I-Q interference correlation matrix.
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41. A method as in claim 30, where performing MMSE optimization comprises operating a frequency domain I-Q pre-whitener that uses a matrix that is synthesized based on an I-Q interference correlation matrix and that outputs pre-whitened signal stream, further comprising processing said pre-whitened signal stream with a sequence detector that combines I-Q branches within a branch metric, and that uses one of Euclidian and Ungerboeck metrics.
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42. A method as in claim 30, where performing MMSE optimization comprises operating a frequency domain I-Q whitener matched filter that uses a matrix that is synthesized based on an I-Q interference correlation matrix and that outputs a whitened signal stream, further comprising processing said whitened signal stream with a sequence detector that combines I-Q branches within a branch metric, and that uses one of Euclidian and Ungerboeck metrics.
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43. A method as in claim 30, where performing MMSE optimization comprises operating an I-Q MMSE Decision Feedback Equalizer (DFE) pre-filter that outputs a pre-filtered signal stream, further comprising operating a reduced state sequence estimator (RSSE) that processes said pre-filtered signal stream
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29. A method as in claim 28, where said signal is received through a single receive antenna, and said RF receiver operates as a single/multi antenna interference cancellation (SAIC) receiver.
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Specification
- Resources
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Current AssigneeNokia Corporation
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Original AssigneeNokia Corporation
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InventorsMCDONNELL, JAMES THOMAS EDWARD, WATERS, JOHN DERYK, Kuchi, Kiran Kumar, Mattellini, Gian Paolo
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Application NumberUS10/641,733Publication NumberTime in Patent OfficeDaysField of SearchUS Class Current375/348CPC Class CodesH04L 2025/0342 QAMH04L 2025/03592 Adaptation methodsH04L 25/03178 Arrangements involving sequ...H04L 25/03267 with decision feedback equa...H04L 25/0328 with interference cancellat...H04L 25/03299 with noise-whitening circuitry