Tensorcomm, Incorporated

Rambus Inc.

III Holdings 1, LLC

Eric S Olson

Anand P Narayan

John K Thomas

Prashant Jain

Anand Narayan

Wolfgang Kober

Robert Kent Krumvieda

Woody Kober

Kent Krumvieda

The present invention is directed to the selective provision of interference canceled signal streams to demodulating fingers in a communication receiver. According to the present invention, potential interferer signal paths are identified. Signal streams having one or more potential interferer signals removed or canceled are created, and a correlation is performed to determine whether the strength of a desired signal path increased as a result. If the correlation indicates that the strength of a desired signal path was increased by the signal cancellation, the interference canceled signal stream is provided to the demodulation finger assigned to track the desired signal path. If the correlation determines that the strength of the desired signal path did not increase as a result of performing interference cancellation, the raw or a different interference canceled signal stream is provided to the demodulation finger.

Method and apparatus for selectively applying interference cancellation in spread spectrum systems

The present invention provides systems and methods for parallel interference suppression. In one embodiment of the invention, a processing engine is used to substantially cancel a plurality of interfering signals within a received signal. The processing engine includes a plurality of matrix generators that are used to generate matrices, each matrix comprising elements of a unique interfering signal selected for cancellation. The processing engine also includes one or more processors that use the matrices to generate cancellation operators. A plurality of applicators applies the cancellation operators to parallel but not necessarily unique input signals to substantially cancel the interfering signals from the input signals. These input signals may include received signals, interference cancelled signals and/or PN codes.

Systems and methods for parallel signal cancellation

A receiver includes a first finger that receives a non-interference-cancelled signal and output first demodulated data, a first phase estimate, and a first PN code. The receiver also includes a second finger that selectively receives the non-interference-cancelled signal and a first interference-cancelled signal generated from the non-interference-cancelled signal based on the first phase estimate and the first PN code. The second finger also outputs second demodulated data.

An interference cancelling receiver combines data from multiple paths after aligning to transmitter timing, and uses either an equalizer or a Rake receiver to compute symbol estimates. Interference estimates are generated from the symbol estimates, and multiple interference estimates are combined after re-aligning the interference estimates to receiver timing. At least two segments of symbol estimates are computed for each segment of interference cancelled data. Various techniques may be employed for controlling the latency and sequencing of these operations, and the subsystems within the canceller may use different processing clock speeds.

Serial cancellation receiver design for a coded signal processing engine

A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal.

Method and apparatus for interference suppression with efficient matrix inversion in a DS-CDMA system

Systems and methods for serial cancellation

The present invention provides systems and methods for interference matrix construction. Such an interference matrix may be used to generate a cancellation operator that when applied to a signal may substantially remove selected interfering signals. In one embodiment of the invention, a system comprises an interference selector configured for selecting one or more interferers for interference cancellation. The system also comprises a matrix generator communicatively coupled to the interference selector and configured for receiving selected interferers from the interference selector. The matrix generator is also configured for generating a matrix having one or more vectors, wherein each vector comprises elements of at least one of the selected interferers. Such an interference matrix and the subsequent generation of the cancellation operator may advantageously provide interference cancellation to systems employing CDMA (e.g., such as cdmaOne and cdma2000), WCDMA, Broadband CDMA, UMTS and GPS signals.

Interference matrix construction

The present invention provides systems and methods for signal cancellation with a receiver. The receiver comprises a discretizer configured for generating digital signals at different resolutions from a received analog signal. Processing fingers of the receiver generate spreading codes from at least one of the digital signals while a Coded Signal Processing Engine ('CSPE') substantially cancels interference from at least another one of the digital signals. The spreading codes are transferred to the CSPE where they may be used to construct an interference matrix. One or more cancellation operators may be generated and subsequently applied to the digital signal(s) input to the CSPE to substantially cancel the interference therefrom. The CSPE may adjust the number of bits of the substantially interference cancelled signal(s) to meet a requisite bit width or dynamic range of the receiver. The substantially cancelled signal(s) is then transferred to the processing fingers for further processing.

Systems and methods for analog to digital conversion with a signal cancellation system of a receiver

The present invention provides systems and methods for parallel interference suppression. A processing engine is used to substantially cancel a plurality of signal paths and selected channel(s) of these signal paths interfering with a selected signal. The processing engine includes a plurality of matrix generators that are used to generate matrices with each matrix comprising elements of one or more of the interfering signal paths and channels selected for cancellation. The processing engine also includes one or more processors for processing the matrices to generate cancellation operators. A plurality of applicators applies the cancellation operators to parallel input signals to substantially cancel the interfering signal from each input signal. These input signals may include received signals and/or reference codes. The embodiments disclosed herein may be particularly advantageous to systems employing CDMA (e.g., such as cdmaOne and cdma), Wideband CDMA, Broadband CDMA, UMTS and Global Positioning System ('GPS') signals.

The present invention is directed to signal cancellation in spread spectrum communication systems. In particular, the present invention provides method and apparatus for selectively canceling interfering signals, even where symbols to be canceled do not align with symbols associated with a desired signal path. Furthermore, the interference cancellation provided by embodiments of the present invention is capable of functioning to remove interference associated with channels utilizing a symbol length that is different than the symbol length of a desired signal path. In accordance with a further embodiment of the present invention, method and apparatus for efficiently calculating projections to enable signal cancellation are provided.

The present invention provides systems and methods for parallel interference suppression. In one embodiment of the invention, a processing engine is used to substantially cancel a plurality of interfering signals within a received signal. The processing engine includes a plurality of matrix generators that are used to generate matrices, each matrix comprising elements of a unique interfering signal selected for cancellation. The processing engine also includes one or more processors that use the matrices to generate cancellation operators. A plurality of applicators applies the cancellation operators to parallel but not necessarily unique input signals to substantially cancel the interfering signals from the input signals. These input signals may include received signals, interference cancelled signals and/or PN codes. The embodiments disclosed herein may be particularly advantageous to systems employing CDMA (e.g., such as cdmaOne and cdma2000), Wideband CDMA, Broadband CDMA and Global Positioning Systems ('GPS') signals.

A novel serial receiver for a wireless communication system is provided. The communication system comprises: a receiver for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor for determining which of the data parameters are sent to respective fingers, wherein the at least two fingers have at least a search finger and a tracking finger; and wherein the tracking finger comprises a correlator and a Coded Signal Processing Engine (CSPE), the CSPE for interference cancellation in the reception of the signal y. In addition, numerous other embodiments of the serial receiver are provided along with methods for using the serial receiver.

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Boulder, CO, United States of America

Eric S Olson