Patents Assigned to SiRF Technology, Inc.
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Publication number: 20130072122Abstract: Systems and methods for channel pairing a transmitter and a receiver are provided. In this regard, a representative method, among others, includes selecting a channel in a radio frequency (RF) band; transmitting a carrier and alert tone on the selected channel in the RF band; responsive to detecting the transmitted carrier and alert tone, demodulating the carrier and alert tone on the selected channel in the RF band and producing the demodulated alert tone; and responsive to detecting the produced alert tone, using the selected channel to establish a wireless link between the transmitter and receiver.Type: ApplicationFiled: November 14, 2012Publication date: March 21, 2013Applicant: SIRF Technology, Inc.Inventor: SIRF Technology, Inc.
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Publication number: 20130021202Abstract: Provided herein are methods and systems for efficient communication between a server and a client in an assisted navigation system. In one or more embodiments, the server transmits a set of parameters for a satellite to the client, e.g., a GPS receiver, via a wireless or wired connection. The set of parameters includes a force parameter, initial condition parameters and time correction coefficients for the satellite. The receiver uses the received parameters in a numerical integration to compute the position of the satellite at a desired time. The set of parameters needed for the integration is small. To further reduce the amount of data transmitted, reference parameters may be subtracted from the original parameters before transmission from the server. The receiver is able to reconstruct the original parameters from the received parameters and the identically computed reference parameters. The parameters may be further compressed using data compression techniques.Type: ApplicationFiled: August 1, 2012Publication date: January 24, 2013Applicants: SIRF TECHNOLOGY, INC.Inventors: Shaowei HAN, Wentao ZHANG
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Patent number: 8260540Abstract: Provided herein are methods and systems for efficient communication between a server and a client in an assisted navigation system. In one or more embodiments, the client, e.g., a GPS receiver, receives a set of parameters for a satellite from the server via a wireless or wired connection. The set of parameters includes a force parameter, initial condition parameters and time correction coefficients for the satellite. The receiver uses the received parameters in a numerical integration to compute the position of the satellite at a desired time. The set of parameters needed for the integration is small compared to current methods which require sending more data to the client. Thus these parameters require less communication resources to transmit. To further reduce the amount of data that needs to be transmitted, reference parameters may be subtracted from the original parameters before transmission from the server.Type: GrantFiled: June 2, 2009Date of Patent: September 4, 2012Assignee: Sirf Technology, Inc.Inventors: Shaowei Han, Wentao Zhang
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Patent number: 8218766Abstract: Systems and methods are provided to facilitate transactions or limit operations. According to one embodiment, region information is determined in accordance with information received by a user device from a local location device. A region requirement is also determined, and it is arranged for the user device to operate in accordance with the region information and the region requirement.Type: GrantFiled: October 16, 2002Date of Patent: July 10, 2012Assignee: Sirf Technology, Inc.Inventor: Anant Sahai
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Patent number: 8151170Abstract: Systems and methods are disclosed herein for improving the sensitivity of satellite data decode in a satellite navigation receiver. The low signal ephemeris data decoding system of the present disclosure achieves a 5 db improvement in decoding sensitivity over conventional system by operating down to a CN0 of 21 dB-Hz. The improved sensitivity is achieved through a combination of reducing the number of data bits to be decoded, overcoming the inherent differential decoding problem of an all data bit polarity inversion, improving the probability of seeing single bit decoding error in an ephemeris word, running the parity correction algorithm, and reducing the undetected word error rate. The improved sensitivity makes it possible to predict the orbit of the satellite and to determine the receiver's location with higher accuracy even when operating in challenging signal conditions.Type: GrantFiled: December 2, 2008Date of Patent: April 3, 2012Assignee: Sirf Technology, Inc.Inventors: Gary Lennen, William Kerry Keal
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Patent number: 8134502Abstract: Systems and methods are disclosed to use adaptive continuous tracking (ACT) to reduce the power consumption of GNSS receivers. In GNSS receivers, a longer observation time of the satellites translates into better positioning accuracy but also consumes more power. 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).Type: GrantFiled: August 13, 2009Date of Patent: March 13, 2012Assignee: SIRF Technology, Inc.Inventor: Gary Lennen
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Patent number: 8111791Abstract: A method for designing a digital filter, includes: (a) selecting a predetermined number of current sets of coefficients for the digital filter; (b) selecting a metric for evaluating coefficients of the digital filter; (c) computing a metric for each current set of coefficients; (d) deriving a next set of coefficients based on a subset of the current set of coefficients; (e) computing the metric for the next set of coefficients; (f) replacing a selected one of the current set of coefficients based on comparing the metric for the next set of coefficients with the metric for the selected current set of coefficients; and (g) iterating steps (a) to (e) until a termination criterion is met. In one embodiment, the selected metric represents a desired stop band response. The next set of coefficients may be derived by adjusting a first current set of coefficients by a weighted difference between a second current set of coefficients and a third current set of coefficients.Type: GrantFiled: December 20, 2006Date of Patent: February 7, 2012Assignee: SiRF Technology, Inc.Inventor: Mark Alan Sturza
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Patent number: 8103289Abstract: A system is described that utilizes the measured characteristics of a cell site or a plurality of cell sites (100, 102, 104) and the cellular identification to selectively provide a wireless device (118) with location aiding from a cellular network server (120). The system may include a basestation (106, 108, 110) located within the cell site, a cellular measurement unit located in the wireless device (118), and a database (214) containing positional assistance information corresponding to the characteristic information. The system may also include a processing unit in signal communication with the basestation and the database (214) and a positional determination unit in the wireless device (118).Type: GrantFiled: May 20, 2011Date of Patent: January 24, 2012Assignee: SIRF Technology, Inc.Inventors: Ashutosh Pande, Lionel Jacques Garin
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Patent number: 8098765Abstract: Methods and systems for processing a Global Positioning System (GPS) signal are provided. A method includes: transforming a time domain GPS signal to a frequency domain GPS signal; storing a frequency domain pseudorandom noise (PRN) signal; correlating the frequency domain GPS signal with the PRN signal at a plurality of frequencies, said correlating including: shifting the frequency domain GPS signal by an amount corresponding to one of the plurality of frequencies; downsampling the shifted frequency domain GPS signal; and multiplying the shifted frequency domain GPS signal by the stored frequency domain PRN signal to produce a correlated signal.Type: GrantFiled: February 23, 2005Date of Patent: January 17, 2012Assignee: SIRF Technology, Inc.Inventors: Paul Eric Beckmann, Andrew Chou, Julien Basch
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Patent number: 8078189Abstract: In a method for providing location-based information over a network, a plurality of GPS reference data sets, corresponding to a plurality of respective local areas, are acquired at intervals such that each GPS reference data set is updated on a continuous basis. A plurality of aiding data sets are generated at intervals based on the respective GPS data sets, whereby each aiding data set is updated on a continuous basis. The generated aiding data sets are stored at intervals on a data-storing network server, whereby updated aiding data sets are available on a continuous basis for access by a requesting entity via communication with the data-storing network server.Type: GrantFiled: March 24, 2005Date of Patent: December 13, 2011Assignee: Sirf Technology, Inc.Inventors: Steve Chang, Ashutosh Pande, Lionel Jacques Garin, Kanwar Chadha, Leon Kuo-Liang Peng, Gengsheng Zhang, Nicolas Patrick Vantalon, Gregory Turetzky
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Patent number: 8069314Abstract: A shared memory architecture for a GPS receiver, wherein a processing memory is shared among the different processing functions, such as the correlator signal processing, tracking processing, and other applications processing. The shared memory architecture within the GPS receiver provides the memory necessary for signal processing operations, such as the massively parallel processing, while conserving memory cost by re-using that same memory for other GPS and non-GPS applications. The shared memory architecture for a GPS receiver provided in accordance with the principles of this invention thereby significantly minimize the costly memory requirement often required of extremely fast signal acquisition of a GPS receiver.Type: GrantFiled: July 18, 2005Date of Patent: November 29, 2011Assignee: SiRF Technology, Inc.Inventors: Leon Kuo-Liang Peng, Henry D. Falk
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Patent number: 8009090Abstract: 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.Type: GrantFiled: May 5, 2009Date of Patent: August 30, 2011Assignee: SiRF Technology, Inc.Inventors: Sanjay Vishin, Steve Gronemeyer
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Publication number: 20110205115Abstract: A wireless device including a transceiver that utilizes a power supply is described. The wireless device includes a Global Positioning System (“GPS”) section having a plurality of GPS subsystems and a power controller in signal communication with the power supply and GPS section, wherein the power controller is configured to selectively power each GPS subsystem from the plurality of GPS subsystems.Type: ApplicationFiled: December 31, 2008Publication date: August 25, 2011Applicant: SiRF Technology, Inc.Inventors: Steven A. Gronemeyer, Mark A. Sturza, Donald Leimer, Sanjai Kohli
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Patent number: 8000723Abstract: A system is described that utilizes the measured characteristics of a cell site or a plurality of cell sites (100, 102, 104) and the cellular identification to selectively provide a wireless device (118) with location aiding from a cellular network server (120). The system may include a basestation (106, 108, 110) located within the cell site, a cellular measurement unit located in the wireless device (118), and a database (214) containing positional assistance information corresponding to the characteristic information. The system may also include a processing unit in signal communication with the basestation and the database (214) and a positional determination unit in the wireless device (118).Type: GrantFiled: February 12, 2010Date of Patent: August 16, 2011Assignee: SiRF Technology, Inc.Inventors: Ashutosh Pande, Lionel Jacques Garin
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Publication number: 20110183606Abstract: A wireless communications device comprises a communication receiver and a positioning system receiver in the wireless mobile communication device. An absolute time signal is received at the positioning system. A network time signal is received at the communication receiver of the wireless mobile communication device. A controller is in signal communication with the position system receiver and the communication receiver. The controller is configured to determine an offset of the absolute time signal from the network time signal and generates a timing mark. The timing mark is tagged by the positioning system receiver with an internal clock value wherein the timing mark has a known relationship with the absolute time signal. A memory stores the offset of the absolute time signal from the network time signal. A transmitter in the wireless mobile communication device transmits the offset for receipt by another wireless mobile communication device.Type: ApplicationFiled: March 24, 2011Publication date: July 28, 2011Applicant: SiRF Technology, Inc.Inventors: Jim Brown, Gengsheng Zhang, Lionel Garin
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Patent number: 7983666Abstract: A cancellation system that delays the received signals and cancels less than all the received signals from the delayed version of the received signals and a demodulator and despreader unit produces a demodulated and de-spreader and remodulator unit produces a remodulated and respread signal from the demodulated and despread signal with a combiner that produces a combined signal from the delayed version of the received signals and the remodulated and respread signal to identify a low power signal.Type: GrantFiled: June 16, 2004Date of Patent: July 19, 2011Assignee: SiRF Technology, Inc.Inventors: Kenneth Scott Walley, Paul A. Underbrink, Steven A. Gronemeyer
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Patent number: 7979207Abstract: Systems and methods for detecting a vehicle static condition are provided. In this regard, a representative system includes a sensor operative to detect at least one of acceleration and angular rate of a vehicle. The sensor is further operative to generate a vehicle vibration profile based on the at least one of the detected acceleration and angular rate of the vehicle. The system further includes a computing device operative to receive the vehicle vibration profile from the sensor, the computing device being further operative to determine whether the vehicle is stationary or moving based on the vehicle vibration profile.Type: GrantFiled: March 19, 2007Date of Patent: July 12, 2011Assignee: SIRF Technology, Inc.Inventors: Mahesh Chowdhary, Qiyue Zhang, Mangesh Chansarkar, Gengsheng Zhang
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Patent number: 7974642Abstract: Systems and methods for estimating a cell center location in a wireless communication system having all interface to a satellite positioning system (“SPS”) such as for example, a Geosynchronous Positioning System (“GPS”). The wireless communication system provides service to mobile stations within a cell, each mobile station includes a SPS receiver. Examples of the systems and methods for estimating a cell center location analyze the mobile station locations in a cell as a uniform distribution of mobile station locations and calculate a statistical measure characterizing the mobile station locations as a function of the mobile station locations. In one example, the statistical measure is a maximum likelihood mobile station location. In another example, the statistical measure is the mean mobile station location in the cell. The estimated cell center location may be used to approximate the location of the mobile station during a warm or cold restart of the SPS receiver part of the mobile station.Type: GrantFiled: February 20, 2007Date of Patent: July 5, 2011Assignee: SiRF Technology, Inc.Inventors: Xiangdong Lin, Mangesh Chambarkar, Marlene Wan, Lionel Garin
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Patent number: 7970412Abstract: An Aided Location Communication System (“ALCS”) is described that may include a geolocation server and a wireless communication device having a GPS section where the GPS receiver section is capable of being selectively switched between a standalone mode and at least one other mode for determining a geolocation of the wireless communications device. An Aided Location Communication Device (“ALCD”) is also described. The ALCD includes a position-determination section having a GPS receiver and a communication section where the position-determination section is selectively switchable between a GPS-standalone mode and at least one other mode for determining a geolocation of the ALCD.Type: GrantFiled: July 20, 2005Date of Patent: June 28, 2011Assignee: SiRF Technology, Inc.Inventors: Ashutosh Pande, Lionel Jacques Garin, Kanwar Chadha, Kurt Christian Schmidt, Leon Kuo-Liang Peng, Gengsheng Zhang, Nicolas Patrick Vantalon, Gregory B. Turetzky
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Patent number: 7969351Abstract: The present invention discloses a system for determining the position of a GPS terminal. The system comprises a GPS terminal, a location aiding server, and a communications system. Messages are passed between the GPS terminal and the server, as well as within the GPS terminal, to determine the mode of operation of the GPS portion of the system. Decisions are made based on availability of aiding data and Quality of Service requirements.Type: GrantFiled: December 4, 2007Date of Patent: June 28, 2011Assignee: SiRF Technology, Inc.Inventors: Ashutosh Pande, Lionel Jacques Garin, Steve Chang Chiayee, Gengsheng Zhang, Randall J. Silva