Abstract: Techniques are provided for synthesizing a long coherent I and Q correlation integral at a particular frequency by synthetically combining a sequence of shorter correlation integrals at the same or different frequency. Techniques are also provided for acquiring a carrier-modulated signal with an unknown shift of the carrier frequency, and possibly some additional unknown signal parameters. These techniques involve synthesizing coherent correlation sums at a fine frequency resolution, using coherent correlation sums that are calculated at a coarse frequency resolution. This approach allows for coherent processing of the received signal over an arbitrarily long time interval, while avoiding the excessive computational requirements of traditional methods.

Abstract: Multifunction satellite positioning receiver having a plurality of functions that are selectable in response to predetermined events or in response to user actions and enable more efficient use of the hardware and processing resources of a multifunction satellite position receiver.

Abstract: Generic SATPS receivers and methods for configuring generic SATPS receivers that include a plurality of outputs are provided. These configurable SATPS receivers are adapted to be utilized in at least one of a plurality of particular SATPS receiver applications, and can also include a plurality of input paths, and a means for generating selected ones of the plurality of possible outputs. Selected ones of the plurality of outputs are enabled/disabled based on at least one requirement of the particular receiver application to configure or program the generic SATPS receiver to function as a SATPS receiver used for a particular SATPS receiver application or operating environment. The selected ones of the plurality of outputs can be defined by and can be those utilized by the particular SATPS receiver application or operating environment.

Abstract: A global positioning receiver unit utilizes a temperature compensated oscillator and a unit controller. The temperature compensated oscillator generates a clock signal, and the unit controller is configured to track GPS time based on the clock signal while the receiver unit is in a sleep state. The unit controller is further configured to perform a position fix based on a satellite signal and the GPS time tracked by the unit controller.

Abstract: Methods and devices for processing GPS signals are provided. The device includes: a memory for storing one or more lookup tables, each lookup table including a plurality of entries, each entry including an input segment and an output segment, wherein the output segment is a system response to the corresponding input segment. The device further includes a processor configured to receive an input data sequence including one or more input segments, and for each of the input segments, retrieve from one of the lookup tables the output segments corresponding to the input segment. The processor is further configured to perform a time-shifted sum of one or more output segments to produce an output sequence that is a downsampled representation of the input data sequence.

Abstract: Devices and methods are described for determining position information without broadcast ephemeris data for extended time periods. A server or client device receives or collects historical state data of satellites of a satellite-based positioning system and generates predictions of future satellite trajectories for future time periods. When a server generates the predictions, the predictions are subsequently transferred to a client device. The client device selects predictions appropriate to time of interest. The time can be any time during a period of at least seven calendar days. The client device reconstructs satellite states using information on the predictions and uses the reconstructed satellite states to acquire satellite signals as appropriate to the current location and time of the client device. The client device determines and/or tracks its position using information of the satellite states and timing information of the satellite signals.

Abstract: Generic SATPS receivers and methods for configuring generic SATPS receivers that include a plurality of outputs are provided. These configurable SATPS receivers are adapted to be utilized in at least one of a plurality of particular SATPS receiver applications, and can also include a plurality of input paths, and a means for generating selected ones of the plurality of possible outputs. Selected ones of the plurality of outputs are enabled/disabled based on at least one requirement of the particular receiver application to configure or program the generic SATPS receiver to function as a SATPS receiver used for a particular SATPS receiver application or operating environment. The selected ones of the plurality of outputs can be defined by and can be those utilized by the particular SATPS receiver application or operating environment.

Abstract: A multi-function device with a positioning function and a real time positioning engine is disclosed. The device contains also a shared processor used by the positioning function and other functions of the device, such as a mobile radio-communication function. The positioning engine performs in real time the most computational intensive calculations of the positioning function, such as downsampling, Doppler mixing and correlation calculations. Since the received signal need not be stored, the memory requirements of the positioning function are significantly reduced if aiding data is available.

Abstract: A two part signal acquisition process includes a parallel signal detection process and signal verification/false alarm rejection process. A massively parallel architecture of acquisition correlators search a large region of the time-frequency uncertainty during the parallel signal detection process to identify the most likely detections for each search dwell. Concurrent with the parallel signal detection process performed by the acquisition correlators, the current list of most likely detections is examined with additional search dwells in the verification/false alarm rejection process. The verification/false alarm rejection process is performed by a plurality of independent correlators or tracking channels. Under software control, the tracking channels perform repeated dwells on the most likely detections until they can be dismissed as false alarms or verified as the desired signal.

Abstract: A CDMA coded, spread spectrum radio signal containing a strong signal and a weak signal is received, and the interference of the strong signal with the weak signal is computed to enhance the ability to track the weak signal. The codes modulating both signals are known, and the weak signal can be predicted. The interference of the strong signal is calculated as the product of the amplitude of the strong signal and the predicted crosscorrelation of the strong signal with the weak signal. The strong signal may be measured, predicted, or acquired through a combination of both methods. The crosscorrelation may be predicted for a range of weak signal values, and the weak signal selected as the prediction producing the greatest received power.

Abstract: The present invention uses at least one amplitude bit to assist the phase-sampling technique used in digital receiver architectures. For digital receivers where the Intermediate Frequency (IF) is an integer multiple of the fundamental frequency fo, the present invention provides reduced processing complexity and reduced power consumption. The present invention allows the digital receiver to avoid performing coordinate rotation at high speeds, and replaces such a coordinate rotation with a simple phase subtraction. This replacement of the coordinate rotation allows the receiver to use a less complicated design, and to consume less power as a result.

Abstract: 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.

Abstract: A method and a system for a location determination (a) acquire a first positioning signal; (b) analyze the first positioning signal to provide an estimate of a clock signal acceleration; (c) acquire additional positioning signals based on the estimate of the clock signal acceleration; and (d) perform the location determination using the first positioning signal and the additional positioning signals. The additional positioning signals may be acquired using a stacking technique. The first positioning signal may be acquired based on a signal-to-noise ratio exceeding a predetermined threshold. Clock signal acceleration may be estimated using a constant clock signal acceleration parametric model, which may be parabolic model based on a function that depends on the clock signal acceleration, a clock Doppler and an initial phase value.

Abstract: A tracker architecture for Global Positioning System (GPS) receivers is disclosed. A typical tracker comprises an RF front end and GPS architecture. The architecture comprises a bus structure, a Central Processing Unit (CPU) core, cache, RAM, and ROM memories, and a GPS engine that comprises a receiving, tracking, and demodulating engine for GPS and Wide Area Augmentation Service (WAAS) signals. The GPS architecture can couple to at least two different protocol interfaces via the bus structure, where the protocol interfaces are commonly used in different applications.

Abstract: A mobile communications device using a common oscillator for communication and global positioning system (GPS) functions. In one embodiment, a communications unit receives a precision carrier frequency signal from a source and generates a reference signal that is used to calibrate a common oscillator.

Abstract: A cellular telephone for use with a cellular telephone network includes a GPS receiver section. Position determination related information is transmitted to and from the cellular telephone using a control channel.

Abstract: System and method to determine the location of a receiver are provided. The received signal is decomposed into signal chunks that are then correlated with the reference signals of the transmitting sources. In some embodiments, the signal chunks may be shorter than the period of the reference signals. For each signal source, a grid of correlation values is constructed containing one column of correlation values for each signal chunk. Each column contains correlation values for several code-phases. Probes are executed in the grid to acquire the location-determining signals. In some embodiments, a probe includes calculating the fourier transform of a row in the grid, yielding correlation values associated with a refined set of frequency values. Potential acquisitions are verified by processing increasing portions of the received signal. Confirmed acquisition may be used to aid further acquisitions.

Abstract: A GPS RF Front End IC using a single conversion stage, which is immune from self jamming from clock signal harmonics generated internally or from dominant clock signal harmonics generated externally by the subsequent baseband GPS processor which uses a clock of 48•fo for GPS processing. The improved frequency plan reduces the problems of interference when the integration of the RF and Baseband functions is required in the form of a single-chip, or as 2 individual chips on a common substrate.

Abstract: Memory reallocation and sharing among components of an electronic system is provided. The electronic system includes a first memory area coupled for access by a first processor via a first bus, and a second memory area coupled for access by a second processor via a second bus. An example system includes a central processor as the first processor and a digital signal processor as the second processor. The electronic system further includes memory configurations that support shared access of the second memory area by the first processor. Using shared access, the first processor can directly access the second memory via the first bus or indirectly access the second memory via the second bus and the second processor. The memory sharing also includes partitioning the shared memory to simultaneously provide the first processor with direct and indirect access to the shared memory.

Abstract: Methods and systems consistent with the present invention provide a host based positioning system. The host based positioning system includes a tracker hardware interface that connects to a dedicated hardware space vehicle tracker. The tracker hardware interface receives positioning information from the space vehicle tracker. The host based positioning system also includes a memory that includes a GPS library having a user interface, a tracker interface, and an operating system interface. A processor runs functions provided by the interfaces.