Sirf Technology, Inc.

Broadcom Corporation

Rf Micro Devices, Inc.

Csr Technology Inc.

Other

Qualcomm Incorporated

Sirf Technology Holdings, Inc.

Charles P Norman

Henry D Falk

Gregory Turetzky

Paul A Underbrink

Keith J Brodie

Anthony James Orler

Charles Robert Cahn

Charles Abraham

Andreas Warloe

Mangesh M Chansarkar

Sundar Raman

James M Brown

Qingwen Zhang

Robert Harvey

Peter Michali

Steven A Gronemeyer

Nicolas Patrick Vantalon

Jared Welz

Vojislav Protic

Stephen F Rounds

Chittharanjan A Dassannacharya

Gensheng Zhang

Shawn Weisenburger

Williams Higgins

Gengsheng Zhang

Richard Gerald Keegan

Jason Matthew Goldberg

William Higgins

Gennaidy Poberezhskiy

Gregory Bret Turetzky

James Brown

Zhang Gengsheng

Zhang Qingwen

Control and feature systems for processing signals from a satellite positioning system include an expert system receiver manager; a joint detection, carrier centring and bit sync acquisition subsystem; peak detection; a multi-dimensional measurement interpolation subsystem; a system for mode switching between a navigational signal; and power control module for receiver.

Control and features for satellite positioning system receivers

Control and feature systems for processing signals from a satellite positioning system include an expert system receiver manager; a joint detection, carrier centering and bit sync acquisition subsystem; peak detection; a multi-dimensional measurement interpolation subsystem; a system for mode switching between a navigational signal; and power control module for receiver.

A direct-sequence spread spectrum (DSSS) receiver may be operable to process signal samples in frequency domain utilizing a prime factor fast Fourier transform (FFT) circuit and a pseudorandom noise (PRN) code. The DSSS receiver may be operable to transform the signal samples into FFT signal samples using the prime factor FFT circuit, transform the PRN code into a FFT PRN code using the prime factor FFT circuit and multiply the FFT signal samples with the FFT PRN code using the prime factor FFT circuit. The DSSS receiver may be operable to inversely transform the multiplied FFT signal samples into correlated signal samples using a prime factor inverse FFT (IFFT) implemented by the prime factor FFT circuit. The prime factor FFT circuit may comprise a prime length FFT core, a FFT memory, a register bank, a switch, a multiplier and a FFT controller.

Method and system for efficient DSSS FFT processing employing prime factor decomposition

A global navigation satellite system (GNSS) receiver may be operable to quantize two-dimensional GNSS sample data with an in-phase (I) and quadrature (Q) pair to two-dimensional quantized data with a magnitude and angle pair using the polar quantization, for example, an unrestricted polar quantization. The GNSS receiver may be operable to reduce a size of the two-dimensional quantized data for storage by representing the two-dimensional quantized data by the one-dimensional symbol data. The one-dimensional symbol data may be stored in a random access memory (RAM) for further processing. The I and Q pair associated with the one-dimensional symbol data stored in the RAM may be retrieved and processed by the GNSS receiver using a correlation such as a fast Fourier transform (FFT) correlation.

Method and system for polar quantization for GNSS data

A signal processing system for processing satellite positioning signals is described. The system comprises at least one processor and a signal processor operating under a number of operational modes. The signal processor includes at least one of a signal processing subsystem, a fast Fourier transform (FFT) subsystem, and a memory subsystem that are each dynamically and independently configurable in response to the operational modes. Further, the system includes a controller that couples to control transfer of data among the signal processing subsystem and the FFT subsystem via the memory subsystem. Configurability of the memory subsystem includes configuring the memory subsystem into regions according to the operational modes where each region is accessible in one of a number of manners according to the operational modes.

Signal processing system for satellite positioning signals

An integrated global navigation satellite system (GNSS) receiver may be operable to decompose GNSS IF signals associated with GPS satellites and/or GLONASS satellites into a constituent narrowband GPS data stream and/or a plurality of constituent narrowband GLONASS data streams utilizing, for example, a GPS IF tuner and/or one or more GLONASS IF tuners. The narrowband GLONASS data streams and/or the narrowband GPS data stream may be processed at reduced sampling rates utilizing a shared sample memory in the integrated GNSS receiver. The narrowband GLONASS data streams and/or the narrowband GPS data stream may be stored in allocated sections of the shared sample memory. The stored narrowband GLONASS data streams and/or the stored narrowband GPS data stream may be processed using a correlation such as a fast Fourier transform (FFT) correlation.

Method and system for integrated glonass and GPS processing

Method and system for integrated GLONASS and GPS processing

Control and feature systems for processing signals from a satellite positioning system include an expert system receiver manager; a joint detection, carrier centering and bit sync acquisition subsystem; peak detection; a multi-dimensional measurement interpolation subsystem; a subsystem for mode switching between a navigational signal; and power control module for a receiver.

The present invention is a combined digital filter and correlator, which is used in a radio frequency (RF) receiver, and takes advantage of common structures used in both digital filters and correlators. Specifically, a digital filter may mix (multiply) digital filter coefficients with samples of a down-converted RF signal, and then sum the resulting products to provide filtered samples of the down-converted RF signal. Similarly, a correlator may mix (multiply) a reference code with the samples of the down-converted RF signal, and then sum the resulting products to provide a correlation of the down-converted RF signal. The present invention combines the digital filter coefficients and the reference code into a modified reference code, which is then mixed with the samples of the down-converted RF signal and summed to provide a filtered correlation of the down-converted RF signal.

Combined digital filter and correlator

A receiver capable of receiving a spread spectrum signal and having a crosscorrelator that enables a carrier wave (CW) jamming to be identified, tracked, replicated and removed from the received spread spectrum signal after demodulation of a weak signal has occurred.

Cross-correlation removal of carrier wave jamming signals

The present invention is a method and apparatus that produces an estimate of the local oscillator (LO) frequency error using an external reference signal. The error estimate can be used for LO calibration, correction and other purposes. The present invention does not require the external reference signal to be a precision reference signal, nor does the present invention require that the reference signal be continuously supplied. Further, the present invention can be implemented exclusively in software, and therefore does not add to the size or weight of any device that it is resident in. Thus, the present invention can be added to microcontrollers and various specialized programmable digital ICs that were not initially designed for this task.

Method and apparatus for estimating local oscillator frequency for GPS receivers

The present invention discloses methods, apparatuses, and systems for eliminating auto- and cross-correlation in weak signal CDMA systems, such as GPS systems. The invention uses parallel data paths that allow standard correlation of signals in parallel with verification of the lock signal to determine whether the system has locked onto the proper signal within the scanned signal window. The invention can be made with multiple CPUs, a single CPU with dual input modes, on multiple IC chips, or as a single IC chip solution for small, low cost reception, downconversion, correlation, and verification systems.

Method for reducing auto-correlation or cross-correlation in weak signals

Communications systems that reduces auto-correlation or cross-correlation in weak signals

The present invention is a method and apparatus for generating a scaled correlation that is based on an estimate of the arrival time of a synchronization point in a received RF signal relative to a sampling clock, which is used to sample the received RF signal after down conversion. The scaled correlation may be used to validate the estimate of the arrival time of the synchronization point and, in certain embodiments of the present invention, may be used to update the estimate of the arrival times for subsequent synchronization points. Using the scaled correlation may provide arrival time estimates with a finer resolution and accuracy than the period of the sampling clock. Such arrival time estimates are important for timing-based applications, such as GPS receivers or navigation receivers.

Received signal correlation using a correlation scaling factor

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Huntington Beach, CA, United States of America

Charles P Norman