Abstract: A system and method for providing temperature compensation in a oscillator component (such as a crystal oscillator component) that includes a closely-located temperature sensing device. The crystal oscillator component in example systems and methods is exposed to a temperature profile during a calibration procedure. Temperature and frequency data are collected and applied to coefficient generating function according to a temperature compensation model to generate a set of coefficients that are used in the temperature compensation model in an application device. The generated coefficients are stored in a coefficient memory accessible to an application device during operation.

Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.

Abstract: The present invention provides systems and methods for navigational signal tracking in low power mode to conserve the power of handheld navigation receivers. In an embodiment, the receiver cycles between sleep and wakeup states. During the sleep state, most of the components of the receiver are powered off to conserve power, and during the wakeup state, the receiver tracks navigational signals. In an embodiment, the duty cycle of the sleep/wakeup states depends on the receiver dynamic state, e.g., whether the receiver is accelerating. In another embodiment, during the wakeup state, the receiver selects a tracking mode based on the signal strength. Under weak signal conditions, a tracking mode using a long integration to track the satellite signal is disclosed. In one embodiment, a tracking mode tracks the navigation signal by performing data aided integration using known or predicted data bits, such as the TLM and HOW words.

Abstract: Systems and methods for calibrating real time clock are provided. A representative receiver includes a GPS device comprising a real time clock (RTC) circuitry that generates RTC clock signals and a temperature compensated crystal oscillator (TCXO) that generates TCXO clock signals. A ratio counter circuitry receives both the RTC clock signals and the TCXO clock signals and determines a frequency ratio by comparing the RTC clock signals and the TCXO clock signals. A computing device receives the frequency ratio and estimates a current RTC frequency based on the received frequency ratio. The computing device is configured to calibrate an estimated RTC time being maintained at the RTC circuitry based on an estimated RTC frequency from a prior estimation, the current RTC frequency and an elapsed time of the RTC circuitry.

Abstract: Devices and methods are described for determining position information without broadcast ephemeris data for extended time periods. A client device is disclosed that stores satellite states determined from broadcast ephemeris and numerically integrates equations of motion with regard to the stored satellite states to determine current satellites states. The client device uses the current satellite states in conjunction with received satellite signals to determine where the satellite signals were received.

Abstract: In one embodiment, a system is provided that is operable to: predict satellite states using historical satellite state data for at least one satellite of a satellite-based positioning system; derive sets of parameters representative of the predicted satellite states; differentially compress the sets parameters into sets of compressed parameters; transmit the sets of compressed parameters to a client device over a first communication channel; uncompress the sets of compressed parameters into sets of recovered parameters; selectively reconstruct at least one reconstructed satellite state in the client device using the sets of recovered parameters; and determine the position of the client device using the at least one reconstructed satellite state along with timing information of satellite data received over a second communication channel.

Abstract: Devices and methods are described for determining position information without broadcast ephemeris data for a spanned time period using predictions of future satellite states. These predictions include predictions of satellite clock bias. During the spanned time period, broadcast ephemeris is received such that a broadcast-ephemeris-derived satellite clock bias may be determined. The predictions of satellite clock bias subsequent to the receipt of the broadcast ephemeris may then be corrected based upon the broadcast-ephemeris-derived satellite clock bias.

Abstract: Provided herein are systems and methods for achieving long integration of an input signal by compensating the frequency and phase of each sample of the input signal. In an embodiment, a Numerical Controlled Oscillator (NCO) of the receiver is modified to include a variable control input that allows the output frequency of the NCO to be adjusted based on a rate of change of frequency. The rate of change of frequency may be estimated based on the relative velocity of a satellite to the receiver computed from satellite orbit parameters or ephemeris. The rate of change of frequency may also be estimated based on frequency measurements of previous samples. The modified NCO may be used as a carrier NCO or code NCO of the receiver to provide frequency and phase compensation of each sample of the input signal.

Abstract: Systems and methods for managing power consumption of a transceiver, e.g., Bluetooth, are provided. A representative transceiver includes an antenna that receives analog radio frequency (RF) signals, and a RF analog circuitry that receives and processes the analog RF signals from the antenna. An analog-to-digital converter (ADC) receives and converts the processed analog RF signals to digital RF signals. A digital circuitry includes a RF power detector that receives the digital RF signals and determines a RF power of the analog RF signals from the antenna based on the digital RF signals. A computing device instructs the RF analog circuitry to operate in low current drain RF receiver mode during page scanning and/or inquiry scanning. The computing device is designed to receive the RF power of the received analog RF signals and manages the power consumption of the transceiver based on the RF power.

Abstract: Systems and methods for tuning an antenna for a frequency modulation (FM) transceiver are provided. A representative system includes: a network of electrical adjustable passive components that receives and sends radio frequency (RF) signals to a receiver circuitry via the network of electrical adjustable passive components. The receiver circuitry determines the received signal strength indication (RSSI) of the RF signal. The system further includes a transmitter circuitry that transmits RF signals via the network of electrical adjustable passive components, and a peak detector circuitry that receives and determines a voltage output of the RF signals from the variable capacitors. An auto-tune circuitry receives the RSSI and output value from the receiver circuitry and the peak detector circuitry, respectively.

Abstract: Systems and methods for detecting global positioning system (GPS) measurement errors are provided. In this regard, a representative system, among others, includes a navigation device that is configured to receive GPS signals from signal sources, the navigation device being configured to calculate pseudoranges (PRs) and delta ranges (DRs) based on the received GPS signals, the navigation device including a consistency check algorithm that is configured to: determine mismatches between the respective calculated PRs and DRs, and indicate that an error exists in the respective calculated PRs and DRs based on their mismatch and mismatch accumulations. This algorithm can be independent of navigation state and is capable of detecting slow-changing errors.

Abstract: 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.

Abstract: Methods and Systems for tracking symbol timing of an OFDM signal are disclosed. In one embodiment, a wireless receiver includes signal tracking and timing logic to facilitate the timing of a demodulation operation such that the demodulation operation occurs on the proper symbol boundary, particularly when the OFDM signal has multipath components and the second component has greater power than the first.

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 includes a layered approach to enable user applications on a host computer to access data from tracker hardware.

Abstract: GPS navigation devices or GPS receivers can consume less power by using a temperature recorder circuit and/or a power manager in maintaining the accuracies of the GPS receiver time and reference frequency to improve battery life. A representative receiver includes a time reference device and the temperature recorder circuit that operate while the receiver hibernates. The time reference device generates clock signals and the temperature recorder circuit receives and operates using the clock signals from the time reference device. The temperature recorder senses the temperature of the time reference device. The temperature recorder circuit is designed to send a wake-up signal to at least one electrical component of the receiver to wake up the electrical component of the receiver. The electrical component of the receiver includes at least one of the following: a GPS signal processing system and a frequency reference device.

Abstract: GPS navigation devices or GPS receivers can consume less power by using a temperature recorder circuit and/or a power manager in calculating the accuracies of the GPS system time and reference frequency to improve battery life. A representative receiver includes a time reference device that generates data associated with a GPS system time, and a temperature recorder circuit that operates using the generated data from the time reference device and monitors the temperature of the time reference device while the receiver hibernates. The receiver further includes memory including a power manager that has instructions, which are processed by a processing device after the receiver wakes up. The instructions associated with the power manager include determining if the temperature recorder circuit sent a wake-up signal, reading data from the temperature recorder circuit, and adjusting parameters associated with at least one of the following: the time reference device and the temperature recorder circuit.

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: An Edge-Aligned Ratio Counter (EARC) that includes at least one processor coupled to at least one counter circuit is provided for determining a ratio between two clock signals by receiving a first and a second value in response to a first clock signal and generating a control signal under control of the loaded value by counting the pulses of the first clock signal and a second clock signal and captures the count of each clock signal in response to the control signal and determining a ratio between a frequency of the first clock signal and a frequency of the second clock signal using the differences of the captured counts taken at two different occurrences of the control signal.

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.

Abstract: An improved time-to-first-fix (TTFF) for GPS systems is provided through a comparison of the time-of-week (TOW) to the sub-frame identification (ID). In one embodiment, this comparison comprises dividing the TOW to form a ratio and performing a modulus operation on the ratio to form a remainder, which is then incremented. If the incremented remainder equals the sub-frame ID, the TOW is assumed to be valid, thereby providing a time of transmission. The time of transmission may then be used to calculate pseudoranges and determine a receiver's location.