Abstract: 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.

Abstract: The present invention is directed to an efficient method and apparatus for channel determination and interference vector construction in accordance with spread spectrum systems. Channel determination is performed using a first series of fast Walsh transform steps. The results of the first set of fast Walsh transform steps corresponding to valid communication system channels are compared to a threshold value. Results derived from the first set of fast Walsh transform steps are then passed through a second set of fast Walsh transform steps with the number of steps performed for a set of results determined by the symbol length associated with the channels from which the amplitude information was derived. The interference vectors thus obtained for each valid symbol length may then be combined to form a composite interference vector. The fast Walsh transform steps and other steps may be performed using shared hardware components or software modules.

Abstract: 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.

Abstract: A controller for advanced receivers configures a plurality of advanced receiver modules based on figures of merit computed on the input signal. The controller also selects the appropriate output signal based on figures of merit of either the input or the output signals. The controller decisions can also be made in a bursty manner, where only a subset of the decisions to be made are made at a given time, thereby limiting the processing load of the control processor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Systems and methods are provided for directionally filtering signals by projecting a received signal onto a subspace substantially orthogonal to selected interfering signals. The received signal typically comprises at least one signal of interest, at least one selected interfering signal, and noise. The received signal may further comprise other signals, including non-selected interfering signals. The projection of the received signal results in substantially no contribution from the selected interference signals on the signal of interest. For example, substantially no residual energy of the selected interference signals remains as an influence on the signal of interest. In one embodiment, a system generates a converted matrix having a substantially orthogonal set of vectors. Each vector may represent one or more selected interfering signals. The vectors may comprise code characteristics of the selected interfering signals. A directional filter uses the matrix to perform the projection.

Abstract: 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.

Abstract: Systems and methods for adjusting phase of a signal are provided. In one embodiment, the system includes a phase compensator configured for adjusting phase of the signal based on filtered and unfiltered representations of a first component of the signal and based on filtered and unfiltered representations of a second component of the signal. For example, the phase compensator may provide phase adjusted I and Q components of a complex signal through a plurality of multiplications of filtered and unfiltered I and Q components. The system also includes a detector that is communicatively coupled to the phase compensator. The detector is configured for combining the first and the second components with a code sequence to determine a complex amplitude of a channel.

Abstract: A novel method and apparatus is provided for enabling the computation of a signal in a certain subspace, its projection that lies outside the subspace, and the orthogonal basis for a given matrix. More particularly, the present invention relates to the use of such a method or apparatus for real-time hardware applications since the method and apparatus may be utilized without matrix inversions or square root computations.

Abstract: Systems and methods for assisting in location estimation are presented. In one embodiment of the invention, a system improves performance of known location determination algorithms through the use of interference cancellation. In general, the system selectively cancels certain signals to improve Signal to Noise Ratios (SNRs) of certain other signals in a spread spectrum system. These improved SNRs enhance processing, which assists in ascertaining a location of a mobile handset. For example, with improved SNR, the handset may be more able to process signals from more base stations. This processing of additional signals can improve location estimation because certain known location determination algorithms can be used (e.g., TOA and AOA) and location ambiguities and can be resolved.

Abstract: 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.

Abstract: The systems and methods described herein provide a processing engine useful in a communications receiver. The processing engine substantially reduces interference caused by unwanted signals by mathematically reducing the energy of the signals. In one embodiment, the signals have known CDMA coding schemes. The signals are selectively substantially cancelled using a matrix generated, at least in part, from determined CDMA codes. For example, a receiver of one embodiment includes a demodulator unit for determining a code from each of a plurality of signals and for demodulating one or more of the plurality of signals. The processing engine is communicatively coupled to the demodulator unit and configured for generating a matrix of one or more vectors based on determined codes. Each element of the vectors comprises a component of the determined codes and the matrix itself is used to selectively substantially reduce energy from one or more of the signals.

Abstract: 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.

Abstract: A novel method and apparatus for determining geolocation of a mobile transmitter is provided. The apparatus and the method utilize an orthogonal projection of a source signal to canceling interference from the source signal in the geolocation process.

Abstract: The present invention is directed to an efficient method and apparatus for channel determination and interference vector construction in accordance with spread spectrum systems. Channel determination is performed using a first series of fast Walsh transform steps. The results of the first set of fast Walsh transform steps corresponding to valid communication system channels are compared to a threshold value. Results derived from the first set of fast Walsh transform steps are then passed through a second set of fast Walsh transform steps with the number of steps performed for a set of results determined by the symbol length associated with the channels from which the amplitude information was derived. The interference vectors thus obtained for each valid symbol length may then be combined to form a composite interference vector. The fast Walsh transform steps and other steps may be performed using shared hardware components or software modules.

Abstract: Systems and methods for adjusting phase of a signal are provided. In one embodiment, the system includes a phase compensator configured for adjusting phase of the signal based on filtered and unfiltered representations of a first component of the signal and based on filtered and unfiltered representations of a second component of the signal. For example, the phase compensator may provide phase adjusted I and Q components of a QPSK signal through a plurality of multiplications of filtered and unfiltered I and Q components. The system also includes a detector that is communicatively coupled to the phase compensator. The detector is configured for combining the first and the second components with a code sequence to determine a magnitude of energy of a channel.