Patents by Inventor Louis L. Scharf
Louis L. Scharf has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9647708Abstract: A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected sub channel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.Type: GrantFiled: August 30, 2010Date of Patent: May 9, 2017Assignee: III HOLDINGS 1, LLCInventors: Louis L. Scharf, Vijay Nagarajan, John K. Thomas
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Patent number: 9036748Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: GrantFiled: November 15, 2013Date of Patent: May 19, 2015Assignee: III HOLDINGS 1, LLCInventors: Vijay Nagarajan, Louis L. Scharf, Anand P. Narayan
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Publication number: 20140314188Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: ApplicationFiled: November 15, 2013Publication date: October 23, 2014Applicant: III Holdings 1. LLC.Inventors: Vijay Nagarajan, Louis L. Scharf, Anand P. Narayan
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Patent number: 8588349Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: GrantFiled: October 5, 2011Date of Patent: November 19, 2013Assignee: Rambus Inc.Inventors: Vijay Nagarajan, Louis L. Scharf, Anand P. Narayan
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Patent number: 8218697Abstract: An OFDMA-MIMO receiver performs a recursive interference cancellation across several correlated subbands and several receive antenna elements to demodulate complex source symbols for several users that have been coded across several subbands and transmit antennas. The iterative parallel interference canceller (PIC) is configured to work in the presence of both spatial and frequency structure introduced by the transmitter space-frequency mapping and the actual frequency selective wireless channel. The interference canceller uses mixed decisions, confidence weights, and stabilizing step sizes in a PIC receiver, which may be used with a successive decoding architecture in a receiver that employs a combination of modulation level interference cancellation with successive decoding.Type: GrantFiled: February 17, 2010Date of Patent: July 10, 2012Assignee: Rambus Inc.Inventors: Tommy Guess, Michael L. McCloud, Louis L. Scharf
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Publication number: 20120027138Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: ApplicationFiled: October 5, 2011Publication date: February 2, 2012Applicant: RAMBUS INC.Inventors: Vijay Nagarajan, Louis L. Scharf, Anand P. Narayan
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Patent number: 8064498Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: GrantFiled: March 19, 2010Date of Patent: November 22, 2011Assignee: Rambus Inc.Inventors: Vijay Nagarajan, Louis L. Scharf, Armand P. Narayan
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Publication number: 20110069796Abstract: A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected sub channel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.Type: ApplicationFiled: December 1, 2010Publication date: March 24, 2011Applicant: RAMBUS INC.Inventors: Louis L. Scharf, Vijay Nagarajan
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Publication number: 20100329402Abstract: A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected sub channel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.Type: ApplicationFiled: August 30, 2010Publication date: December 30, 2010Applicant: RAMBUS INC.Inventors: Louis L. Scharf, Vijay Nagarajan, John K. Thomas
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Patent number: 7787572Abstract: A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected subchannel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.Type: GrantFiled: August 15, 2005Date of Patent: August 31, 2010Assignee: Rambus Inc.Inventors: Louis L. Scharf, Vijay Nagarajan
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Publication number: 20100208854Abstract: An OFDMA-MIMO receiver performs a recursive interference cancellation across several correlated subbands and several receive antenna elements to demodulate complex source symbols for several users that have been coded across several subbands and transmit antennas. The iterative parallel interference canceller (PIC) is configured to work in the presence of both spatial and frequency structure introduced by the transmitter space-frequency mapping and the actual frequency selective wireless channel. The interference canceller uses mixed decisions, confidence weights, and stabilizing step sizes in a PIC receiver, which may be used with a successive decoding architecture in a receiver that employs a combination of modulation level interference cancellation with successive decoding.Type: ApplicationFiled: February 17, 2010Publication date: August 19, 2010Inventors: Tommy Guess, Michael L. McCloud, Louis L. Scharf
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Patent number: 7697595Abstract: A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal.Type: GrantFiled: May 11, 2006Date of Patent: April 13, 2010Assignee: Tensorcomm IncorporatedInventors: Vijay Nagarajan, Louis L Scharf, Anand P Narayan
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Patent number: 7463609Abstract: 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.Type: GrantFiled: July 29, 2005Date of Patent: December 9, 2008Assignee: Tensorcomm, IncInventors: Louis L. Scharf, Vijay Nagarajan