Abstract: A method and apparatus for obtaining Global navigation Satellite System (GNSS) time in a GNSS receiver are provided. The following steps are included: obtaining a time relationship between a first clock signal and the received GNSS time; obtaining a first clock value of a second clock signal and an first associated clock value of the first clock signal at a first time point; calculating a first GNSS time corresponding to the first clock value of the second clock signal according to the first associated clock value and the time relationship; obtaining a second clock value of the second clock signal and an second associated clock value of the first clock signal at a second time point; and calculating a second GNSS time corresponding to the second associated clock value, according to the first GNSS time, the first clock value and the second clock value of the second clock signal.
Abstract: A method for adjusting a measurement cycle in a satellite signal receiver is described. The method includes adjusting a measurement cycle in a satellite signal receiver by computing a position state comprising at least one of a velocity and a heading of the satellite signal receiver, detecting a change in the position state, and automatically adjusting a frequency of the measurement cycle in response to the change in the position state.
Abstract: Provided is a navigator, which reduces current consumption in a gap of an orbiting GPS satellite signal. A method for reducing the current consumption of the navigator is disclosed. The method includes measuring the strength of a geostationary GPS satellite signal; stopping the tracking of an orbiting GPS satellite signal when the measured geostationary GPS satellite signal strength is less than a critical value and such a state passes a preset time; performing a navigation mode where an orbiting GPS satellite signal and a geostationary GPS satellite signal are tracked when the measured geostationary GPS satellite signal strength exceeds the critical value. The navigator reads a gap of an orbiting GPS satellite signal using a geostationary GPS satellite signal and stops tracking the orbiting GPS satellite signal in the gap, thereby reducing its current consumption.
Abstract: Aspects of a method and system for maintaining a GNSS receiver in a hot-start state are provided. A GNSS receiver in a standby mode may transition from a sleep state to a wakeup state to acquire ephemeris from, for example, GPS signals, GALILEO signals, and/or GLONASS signals. The acquired ephemeris may be stored and utilized for the GNSS receiver to generate a navigation solution in a normal mode. The GNSS receiver may transition from the normal mode to the sleep state or the wakeup state in standby mode. A sleep period and a wakeup period for the full sleep-wakeup cycle in the standby mode may be predetermined or dynamically adjusted based on required QoS, quality of satellite signals, and/or user inputs. The sleep period and the wakeup period may be selected in a way to ensure a valid and complete ephemeris to be acquired.
Abstract: 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 last 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.
Type:
Application
Filed:
September 2, 2004
Publication date:
May 5, 2011
Applicant:
SIRF TECHNOLOGY, INC.
Inventors:
Paul A. Underbrink, Henry D. Falk, Steven A. Gronemeyer, Chittharanjan Dassannacharya, Charles P. Norman, Nicolas Vantalon, Vojislav Protic
Abstract: A method for determining portions of a GPS satellite signal may use non-coherent integration to determine a repeated pattern such as a preamble. Once the repeated pattern is determined, portions of the GPS satellite signal that may be determined with partial correlation sums. Sensitivity to satellite signals may be increased by computing more partial correlation sums on portions of the GPS satellite signal. In one embodiment, time of day information may be determined from the GPS satellite signal with partial correlation sums.
Abstract: Methods and systems are disclosed for enhancing line records with Global Positioning System coordinates. Global Positioning System information is acquired and a line record is assembled for an address using the Global Positioning System information.
Type:
Grant
Filed:
July 31, 2009
Date of Patent:
April 26, 2011
Assignee:
AT&T Intellectual Property I, L. P.
Inventors:
Robert M. Ingman, Charles E. Reddick, Steven G. Smith, Marvin R. Hamrick
Abstract: An execution method of a position calculating circuit that calculates a position by receiving a satellite signal transmitted from a positioning satellite and that has an externally readable storage section includes: receiving a selection signal for selecting acquired information, which is information acquired from information obtained from the satellite signal, from the outside; selecting the acquired information on the basis of the selection signal; and storing the acquired information in the storage section and outputting a notice signal, which indicates that the acquired information has been obtained, when the acquired information selected from the satellite signal being received is obtained.
Abstract: The use of multiple GPS sensors provides the conceptual framework for novel techniques for reducing the minimum signal strength required by a GPS assistance system to acquire and accurately track GPS satellites at or near the horizon. A strong signal attenuation system for synthesizing GPS satellite-specific I/F signals, enabling more efficient and effective acquisition of GPS satellites, is disclosed, comprising N+1 reference GPS sensors, each with an omni-directional antenna and front end, for down converting composite GPS satellite signals, and strong signal suppression (SSS) means for synthesizing, from the I/F signals produced by the N+1 reference GPS sensors, a set of one or more I/F signals (corresponding to a set of designated satellites), each with at least N of the strongest potentially-interfering satellite signals suppressed.
Type:
Application
Filed:
October 2, 2009
Publication date:
April 7, 2011
Inventors:
Farrokh Farrokhi, Dickson T. Wong, Arthur J. Collmeyer
Abstract: A method for calculating current position coordinate is applied to a global positioning system (GPS) receiver. When positioning at a current time point, the GPS receiver directly calculates a code delay and a carrier frequency of each satellite and position coordinate of the GPS receiver at a current positioning time point by utilizing an ephemeris data of each satellite and position coordinate of the GPS receiver at a last positioning time point, thereby greatly lowering an operation amount, so as to reduce the power consumption.
Abstract: A method for determining a bit boundary of a repetition-coded signal including bits each having a plurality of epochs includes (a) counting the epochs repeatedly from an initial number to a predetermined number in a predetermined time, (b) sensing sign changes in the epochs, (c) recording each sensed sign change with a weighting function to a corresponding counting number of the epoch, and (d) determining the bit boundary according to a result of step (c).
Abstract: A satellite signal adaptive time-division multiplexing receiving device is disclosed. The receiving device operates in time-division multiplexing distributed for various domains such as satellite number, Doppler frequency, code phase and accuracy. When some specific time slots of the time-division multiplexing distribution are unnecessary to be searched, the receiving device uses a disable signal to deactivate specific components such as correlator and memory thereof during those time slots to reduce power consumption.
Abstract: A method for obtaining GNSS time in a GNSS receiver includes: obtaining a time relationship between a first clock signal and the received GNSS time; obtaining a clock value B1 of a second clock signal and further obtaining an associated clock value A1 of the first clock signal to obtain a first pulse relationship at a first time point; calculating a GNSS time C1 corresponding to the clock value A1 according to the time relationship; obtaining a clock value B2 of the second clock signal and further obtaining an associated clock value A2 of the first clock signal to obtain a second pulse relationship at a second time point; and calculating a GNSS time C2 according to the GNSS time C1, the clock value B1, and the clock value B2. Exemplary values of A1, B1, C1, A2 B2, and C2 can be TTick1, FN1, TOW1, TTick2, FN2, and TOW2, respectively.
Abstract: Systems and methods are disclosed herein to use what is referred to as adaptive continuous tracking (ACT) to reduce the power consumption of GNSS receivers. In GNSS receivers, performance as measured by position accuracy is a function of the observation time of the satellites. A longer observation time translates into more reliable range measurements and demodulated data, and ultimately into better positioning accuracy of the receivers. However, a longer observation time also means more power consumption. ACT allows satellite observation time to be tuned to the desired positioning performance by dynamically adjusting the on time period of the receivers while maintaining a minimum performance metric. The performance metric may be formed from a combination of the estimated position error, the horizontal dilution of precision (HDOP), the data collection state, and the receiver operating environment as characterized by the carrier to noise ratio (CN0).
Abstract: A method for tracking a satellite signal by a GPS includes the following steps. Data is continuously received from one of satellites by using tracking frequencies updated one by one based on an average phase difference of received data. Phase inversion points in the plurality of received data are interpreted. A time difference between each two adjacent phase inversion points among the phase inversion points is calculated. It is determined whether each time difference is an integral multiple of 20 ms. When each time difference is an integral multiple of 20 ms, 1-bit data is retrieved for every 20 ms from the satellite signal by taking a first phase inversion point among the plurality of phase inversion points as a starting point. Thus, a positioning speed is increased and a required positioning time is reduced by finding out a precise tracking frequency and a correct phase inversion point.
Abstract: The location of a mobile terminal in a given area is determined by including the mobile terminal both in a satellite-based positioning system and in a cellular communications system. The mobile terminal is thus adapted to receive satellite signals from the satellite-based system and to be covered by at least one cell of the cellular communications system. The mobile terminal is configured for determining at least approximately its coordinates, including an altitude coordinate in the area, based on both satellite signals received from the satellite-based system and information related to the cellular communications system. An estimate of the altitude coordinate is derived from the information related to the cellular communications system, whereby satisfactory location performance is ensured also when one or more satellites in the satellite-based system are not visible at the mobile terminal.
Abstract: Disclosed is an apparatus, system and method for location determination following a search discontinuity utilizing early sampling of a satellite positioning system signal to determine a common code phase offset, pseudorange rate and mode of location calculation.
Type:
Application
Filed:
March 5, 2010
Publication date:
January 6, 2011
Applicant:
QUALCOMM Incorporated
Inventors:
Dominic Gerard Farmer, Lalitaprasad V. Daita, Jie Wu
Abstract: The present invention provides systems and methods for enabling a navigation signal receiver to perform both data assisted and non-data assisted integration to provide better integration during signal acquisition, reacquisition and tracking. In data assisted integration mode, a receiver uses known or predicted data bits to remove the modulated data bits of a received signal prior to integration. In non data assisted integration mode, when the data bits are not known or predictable, the receiver uses an optimal estimation or maximum likelihood algorithm to determine the polarities of the modulated data bits of the received signal. This may be done by determining which of various possible bit pattern yields the maximum integrated power. When the modulated data bits are not known or predictable over a limited range, the receiver carries out data assisted integration over the known or predictable data bits and additional non data assisted integration.
Abstract: Systems and methods are disclosed herein to dynamically vary supply voltages and clock frequencies, also known as dynamic voltage scaling (DVS), in GPS receivers to minimize receiver power consumption while meeting performance requirements. For the baseband circuitry performing satellite acquisition and tracking, supply voltages and clock frequencies to the baseband circuitry are dynamically adjusted as a function of signal processing requirements and operating conditions for reducing baseband power consumption. Similarly, the supply voltage and clock frequency to the processor running navigation software and event processing are dynamically adjusted as a function of navigation performance requirements and event occurrences to reduce processor power consumption.
Abstract: The present invention provides a method and apparatus for providing simplified seismological surveys with increased accuracy and ease of use. The present invention uses data received from satellite positioning systems to obtain time and position information. The information is used to determine transmission times of pressure waves between a seismic source and a seismic sensor.
Abstract: A device tracking system for tracking location coordinates of a portable device in real time is provided. The system includes a microprocessor chip in which a GPS transceiver is embedded. The microprocessor chip is installed in the portable device. The system also includes at least one GPS satellite capable of communicating with the GPS transceiver for obtaining location coordinates of the portable device, at least a second GPS transceiver coupled with the GPS satellite via a satellite antenna for receiving the obtained location coordinates; and a computer server coupled with the second GPS transceiver for communicating the obtained location coordinates to an authorized user via a web-enabled program.
Abstract: A time adjustment device has a reception unit that receives a satellite signal transmitted from a positioning information satellite, a time information generating unit that generates internal time information, and a time information adjustment unit that adjusts the internal time information. The satellite signal contains satellite time information that is kept by the positioning information satellite. The reception unit includes a signal level acquisition unit that searches for positioning information satellites and acquires the signal level of the satellite signal transmitted from each positioning information satellite, a reception satellite selection unit that selects a positioning information satellite based on the acquired signal level, and a satellite time information acquisition unit that receives the satellite signal transmitted from the positioning information satellite selected by the reception satellite selection unit, and acquires the satellite time information contained in the satellite signal.