Interference cancellation within wireless transceivers
First Claim
1. A CDMA receiver, comprisinga baseband front-end configured to perform baseband processing on a received baseband signal,a descrambler located downstream from the baseband front-end,a despreader located downstream from the descrambler,an interference selector configured to select at least one interfering symbol from at least one of the descrambler and the despreader for producing at least one selected interference symbol,a synthesizer coupled to the interference selector and configured to synthesize an interference signal from the at least one selected interference symbol,a channel emulator configured for imparting at least one channel distortion to the at least one interference signal, anda canceller located downstream from at least one of the baseband front-end, the descrambler, and the despreader.
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Accused Products
Abstract
The receiver includes a Rake receiver for separating a received signal into multipath components, an interference selector for selecting interference symbols corresponding to interfering paths and subchannels, a synthesizer for synthesizing an interference signal from selected paths and estimated subchannel symbols, and a canceller for constructing a projection operator or a scale-invariant subtraction operator to cancel selected interference in multipath components of the received signal, or from the received signal itself. The interference canceller may use a sequence of symbol estimates to simultaneously cancel inter-channel interference and inter-symbol interference. Interference cancellers may be placed at one or more locations within the receiver chain.
201 Citations
21 Claims
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1. A CDMA receiver, comprising
a baseband front-end configured to perform baseband processing on a received baseband signal, a descrambler located downstream from the baseband front-end, a despreader located downstream from the descrambler, an interference selector configured to select at least one interfering symbol from at least one of the descrambler and the despreader for producing at least one selected interference symbol, a synthesizer coupled to the interference selector and configured to synthesize an interference signal from the at least one selected interference symbol, a channel emulator configured for imparting at least one channel distortion to the at least one interference signal, and a canceller located downstream from at least one of the baseband front-end, the descrambler, and the despreader.
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8. A CDMA reception method, comprising
providing for baseband front-end processing of a received baseband signal for producing a digitized received baseband signal, providing for descrambling the digitized received baseband signal for producing a descrambled baseband signal, providing for despreading the descrambled baseband signal for producing a despread baseband signal, providing for selecting at least one interfering symbol from at least one of the descrambled baseband signal and the despread baseband signal for producing at least one selected interference symbol, providing for synthesizing an interference signal from the at least one selected interference symbol, providing for imparting at least one channel distortion to the at least one interference signal, and providing for cancellation located downstream from at least the baseband front-end processing.
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16. A CDMA receiver, comprising
means for baseband front-end processing of a received baseband signal for producing a digitized received baseband signal, means for descrambling the digitized received baseband signal for producing a descrambled baseband signal, means for despreading the descrambled baseband signal for producing a despread baseband signal, means for selecting at least one interfering symbol from at least one of the descrambled baseband signal and the despread baseband signal for producing at least one selected interference symbol, means for synthesizing an interference signal from the at least one selected interference symbol, means for imparting at least one channel distortion to the at least one interference signal, and means for cancellation located downstream from at least the baseband front-end processing.
Specification