Iterative interference cancellation using mixed feedback weights and stabilizing step sizes
First Claim
1. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
- a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom;
a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; and
a stabilizing step size module configured to scale the error signal by a stabilizing step size to produce a scaled error signal.
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Accused Products
Abstract
A receiver is configured for canceling intra-cell and inter-cell interference in coded, multiple-access, spread-spectrum transmissions that propagate through frequency-selective communication channels. The receiver employs iterative symbol-estimate weighting, subtractive cancellation with a stabilizing step-size, and mixed-decision symbol estimate. Receiver embodiments may be implemented explicitly in software of programmed hardware, or implicitly in standard Rake-based hardware either within the Rake (i.e., at the finger level) or outside the Rake (i.e., at the user of subchannel symbol level).
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Citations
67 Claims
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1. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; and a stabilizing step size module configured to scale the error signal by a stabilizing step size to produce a scaled error signal. - View Dependent Claims (2, 3, 4, 6, 8, 9, 10, 11, 12, 18, 21, 22)
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5. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; and a weighting module configured to multiply input symbol estimates by weights having magnitudes derived from merits of the input symbol estimates.
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7. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; and a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; wherein the constituent signals are characterized by at least one of a set of signals, the set comprising received signals associated with a plurality of Rake fingers and received signals associated with a plurality of symbol sources.
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13. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; and a decision module configured to produce a decision for at least one of the symbol estimates, the decision selected from one of a hard decision quantizing at least one of the symbol estimates to a nearby constellation point, and a soft decision, scaling, but not quantizing, the at least one of the symbol estimates. - View Dependent Claims (14)
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15. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; and a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; wherein the suppressor is configured for performing synthesis and resolution into one or more constituent signals corresponding to each of the sources in the channel in an outer feedback loop, and updating symbol estimates in an inner feedback loop employing an implementation matrix. - View Dependent Claims (16, 17)
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19. An interference suppressor for suppressing interference in a received signal from a channel, the suppressor configured for performing at least one iteration to produce at least one interference-suppressed symbol estimate, the suppressor comprising:
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a synthesizing module configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and to produce a combined signal therefrom; and a subtraction module configured to subtract the combined signal from the received signal to produce an error signal; wherein the suppressor is configured for performing symbol-level interference suppression on despread signals with a one-step matrix update equation expressing a representation of user correlations, an implementation matrix, a soft-weighting matrix, a de-biasing matrix, and a scalar stabilizing step size. - View Dependent Claims (20)
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23. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; subtract the combined signal from the received signal to produce an error signal; and scale the error signal by a stabilizing step size to produce a scaled error signal. - View Dependent Claims (24, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 41, 44, 45)
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28. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; subtract the combined signal from the received signal to produce an error signal; and weight by multiplying input symbol estimates by weights having magnitudes derived from merits of the symbol estimates.
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30. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
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configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; and subtract the combined signal from the received signal to produce an error signal; wherein the constituent signals are characterized by at least one of a set of signals, the set comprising received signals associated with a plurality of Rake fingers and received signals associated with a plurality of symbol sources.
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36. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
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configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; subtract the combined signal from the received signal to produce an error signal; produce a decision for at least one of the symbol estimates, the decision selected from one of a hard decision quantizing at least one of the symbol estimates to a nearby constellation point, and a soft decision, scaling, but not quantizing, the at least one of the symbol estimates.
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38. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
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configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; subtract the combined signal from the received signal to produce an error signal; perform synthesis and resolution onto one or more constituent signals corresponding to each of the sources in the channel in an outer feedback loop, and update symbol estimates in an inner feedback loop employing an implementation matrix. - View Dependent Claims (39, 40)
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42. An interference suppression method for suppressing interference in a received signal from a channel, the method configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the method comprising:
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configuring a processor to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates; produce a combined signal therefrom; subtract the combined signal from the received signal to produce an error signal; and perform symbol-level interference suppression on despread signals with a one-step matrix update equation expressing a representation of user correlations, an implementation matrix, a soft-weighting matrix, a de-biasing matrix, and a scalar stabilizing step size. - View Dependent Claims (43)
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46. An interference suppression system for suppressing interference in a received signal from a channel, the system configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the system comprising:
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a synthesizing means configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and producing a combined signal therefrom; a subtraction means configured to subtract the combined signal from the received signal to produce an error signal; and a stabilizing step size means configured for scaling the error signal by a stabilizing step size to produce a scaled error signal. - View Dependent Claims (47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)
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50. An interference suppression system for suppressing interference in a received signal from a channel, the system configured for performing at least one iteration to produce an interference-suppressed symbol estimate, the system comprising:
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a synthesizing means configured to synthesize one or more constituent signals corresponding to one or more sources in the channel from a plurality of symbol estimates, and producing a combined signal therefrom; a subtraction means configured to subtract the combined signal from the received signal to produce an error signal; and a weighting means configured to multiply input symbol estimates by weights having magnitudes derived from merits of the one or more symbol estimates.
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Specification