Patents Assigned to SIRF Technology
  • Patent number: 6593897
    Abstract: A wireless apparatus includes an electrically conductive casing housing a ground plane and GPS receiver circuitry. The casing is electrically connected to the ground plane to form a first antenna element. The apparatus further includes a second antenna element located external the casing. The second antenna element may be configured as a wire filament in the form of a copper trace carried by a printed circuit board. The second antenna element is electrically coupled to the first antenna element and the GPS receiver circuitry. The first antenna element and second antenna element are configured and disposed relative to each other to form an antenna for receiving GPS signals.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: July 15, 2003
    Assignee: Sirf Technology, Inc.
    Inventor: Richard J. McConnell
  • Patent number: 6577271
    Abstract: A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: June 10, 2003
    Assignee: Sirf Technology, INC
    Inventor: Steven A. Gronemeyer
  • Patent number: 6574558
    Abstract: A terrestrial C/A code GPS receiver system derives along-track position information while tracking as few as two GPS satellites by use of conventional altitude hold and a cross-track hold mode in which the maximum expected deviation of the vehicle from the expected track is estimated by, for example, knowledge or prediction of the width of the roadway or other track. To maintain accuracy, cross-track hold is alternated with clock hold to update the cross-track estimate when changes in vehicle direction are detected or when a predetermined period has elapsed.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: June 3, 2003
    Assignee: Sirf Technology, Inc.
    Inventor: Sanjai Kohli
  • Patent number: 6542823
    Abstract: The present invention discloses a GPS system that can operate in different modes depending on the network facilities and bandwidth available, the GPS information that can be acquired, or user or system requirements. The modes comprise standalone mode, where a mobile communications device computes the position of the device, an autonomous mode, where the mobile communications device transmits the computed position to a server, application, or PSAP in a communications network, a network aided mode, where the network aides the mobile communications device in deter mg the position of the device, a network based mode, and other modes.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: April 1, 2003
    Assignee: SiRF Technology, Inc.
    Inventors: Lionel Jacques Garin, Kanwar Chadha, Gregory Bret Turetzky, Ashutosh Pande
  • Patent number: 6539304
    Abstract: A GPS receiver includes a satellite receiver/processor having an input that receives input signals from at least one GPS satellite. The output of the receiver/processor provides satellite-related navigation information. A neural network receives the satellite-related information to obtain an output signal representative of receiver-related navigation information. The neural network includes a first node layer connected to a second node layer through a first connection layer and a third node layer connected to the second node layer through a second connection layer. Each of the node layers comprises a plurality of neurons.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: March 25, 2003
    Assignee: SiRF Technology, Inc.
    Inventor: Mangesh M. Chansarkar
  • Patent number: 6531982
    Abstract: A system is provided for communicating location and other related information of a field unit to a remote base station. The field unit generates position signals based on signals received from communication with a plurality of GPS satellites. These position signals are transmitted to a remote base station, where they are processed and displayed. The field unit includes an environmental circuit having devices for determining an environmental condition and producing an environmental signal representative of the environmental condition. The environmental signal is also transmitted to the remote base station for processing and display. The field unit is also provided with a cellular link circuit for transmitting the position signals and the environmental signal to the remote base station via a cellular link.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: March 11, 2003
    Assignee: SiRF Technology, Inc.
    Inventors: Stanley A. White, Kenneth S. Walley, James W. Johnston, P. Michael Henderson, Kelly H. Hale, Warner B. Andrews, Jr., Jonathan I. Siann
  • Patent number: 6529829
    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.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: March 4, 2003
    Assignee: SIRF Technology, Inc.
    Inventors: Gregory Bret Turetzky, Charles P. Norman, Henry D. Falk
  • Patent number: 6526322
    Abstract: 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: Grant
    Filed: December 16, 1999
    Date of Patent: February 25, 2003
    Assignee: SiRF Technology, Inc.
    Inventors: Leon Kuo-Liang Peng, Henry D. Falk
  • Patent number: 6522682
    Abstract: A spread spectrum receiver processes signals from a plurality of sources modulated by different spread spectrum codes by sampling the signals as received to produce an integer series of sampling segments at a sampling rate at least twice a chip rate of the codes, each sampling segment containing an integer number of bits representing a fraction of a chip of the codes, time division multiplexing each sample segment into a number of channels, correlating the bits in each sample segment in each channel in parallel with a source specific series of locally generated sequential code samples differing by one bit, summing each parallel correlation, and accumulating the summed parallel correlations for each code sample in each channel at at least the chip rate to derive data related to each of the sources.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: February 18, 2003
    Assignee: SiRF Technology, Inc.
    Inventors: Sanjai Kohli, Steven Chen
  • Patent number: 6519277
    Abstract: A mobile wireless transceiver selects one of multiple nearby base stations to facilitate communication over a wireless network. Each base station transmits a pilot signal that includes a spreading signal transmitted at one of many possible phase offsets. The wireless transceiver selects an initial one of the possible phase offsets of the spreading signal and then correlates a received signal against the spreading signal at consecutive ones of the possible phase offsets. Correlation begins at the selected initial phase offset and continues until a component of the received signal and the spreading signal are aligned, indicating the detection of the pilot signal from one of the base stations.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: February 11, 2003
    Assignee: SiRF Technology, Inc.
    Inventor: Donald Brian Eidson
  • Patent number: 6519466
    Abstract: The present invention discloses a GPS system that can operate in different modes depending on the network facilities and bandwidth available, the GPS information that can be acquired, or user or system requirements. The modes comprise standalone mode, where a mobile communications device computes the position of the device, an autonomous mode, where the mobile communications device transmits the computed position to a server, application, or PSAP in a communications network, a network aided mode, where the network aides the mobile communications device in determining the position of the device, a network based mode, and other modes.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: February 11, 2003
    Assignee: Sirf Technology, Inc.
    Inventors: Ashutosh Pande, Lionel Jacques Garin, Kanwar Chadha, Gregory Bret Turetzky
  • Publication number: 20030011512
    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.
    Type: Application
    Filed: September 16, 2002
    Publication date: January 16, 2003
    Applicant: SiRF Technology, Inc.
    Inventors: Gregory Bret Turetzky, Charles P. Norman, Henry D. Falk
  • Publication number: 20020190896
    Abstract: The present invention discloses a GPS system that uses call-processor intelligence to determine the mode of operation of a GPS receiver located in a GPS terminal. The modes are selected based on the availability of network facilities, the GPS information that can be acquired, or user input requirements.
    Type: Application
    Filed: August 7, 2002
    Publication date: December 19, 2002
    Applicant: SiRF Technology, Inc. and Matsushita Electric Works, Ltd.
    Inventors: Ikuo Tsujimoto, Junichi Suzuki, Chiayee Steve Chang, Lionel Jacques Garin, Ashutosh Pande
  • Patent number: 6496145
    Abstract: A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: December 17, 2002
    Assignee: SiRF Technology, Inc.
    Inventor: Steven A. Gronemeyer
  • Publication number: 20020183076
    Abstract: The present invention discloses a GPS system that can operate in different modes depending on the network facilities and bandwidth available, the GPS information that can be acquired, or user or system requirements. The modes comprise standalone mode, where a mobile communications device computes the position of the device, an autonomous mode, where the mobile communications device transmits the computed position to a server, application, or PSAP in a communications network, a network aided mode, where the network aides the mobile communications device in determining the position of the device, a network based mode, and other modes.
    Type: Application
    Filed: July 12, 2002
    Publication date: December 5, 2002
    Applicant: SiRF Technology, Inc.
    Inventors: Ashutosh Pande, Lionel Jacques Garin, Kanwar Chadha, Gregory B. Turetzky
  • Patent number: 6480150
    Abstract: An autonomous Hardwired Tracking Loop (HWTL) ASIC comprising a HWTL coprocessor provided for implementing most of the receiver processing function for data acquisition and tracking functions of a radio receiver system in dedicated hardware. With the expanded functionality provided by an HWTL coprocessor in the autonomous HWTL ASIC, the interruption of CPU performing the navigation processing is significantly reduced to thereby maximize throughput and minimize power burden on the microprocessor. In the preferred embodiment, the HWTL ASIC also comprises the CPU and a correlator, wherein the correlator provides the high rate greater than approximately 1 KHz signal processing operations, the HWTL coprocessor providing the data acquisition and tracking (medium frequency signal processing) operations, and the CPU thereby freed to provide more bandwidth for lower frequency processing, i.e.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: November 12, 2002
    Assignee: SiRF Technology, Inc.
    Inventors: Henry D. Falk, Leon Kuo-Liang Peng, Wesley F. Marumo
  • Patent number: 6466161
    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.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: October 15, 2002
    Assignee: SIRF Technology, Inc.
    Inventors: Gregory Bret Turetzky, Charles P. Norman, Henry D. Falk
  • Patent number: 6466612
    Abstract: A GPS receiver system determines the presence of trackable signals at code delays less than the prompt delay being tracked for a particular signal and changes the prompt delay to correspond to the smallest code delay having a trackable signal. Trackable signals at large code delays are multipath signals and may be separately tracked to aid in dead reckoning. The trackable signals at code delays not adjacent to the currently tracked prompt delay may be tracked in the same channel as the prompt delay so that all satellite channels are continuously evaluated for multipath signals being tracked or a non-satellite specific channel may be used to sequentially step through the satellite signals to evaluate multipath on a satellite by satellite basis.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: October 15, 2002
    Assignee: SiRF Technology, Inc.
    Inventors: Sanjai Kohli, Charles R. Cahn
  • Publication number: 20020145560
    Abstract: The present invention discloses a GPS system that uses call-processor intelligence to determine the mode of operation of a GPS receiver located in a GPS terminal. The modes are selected based on the availability of network facilities, the GPS information that can be acquired, or user input requirements.
    Type: Application
    Filed: April 5, 2001
    Publication date: October 10, 2002
    Applicant: SiRF Technology, Inc.
    Inventors: Ikuo Tsujimoto, Junichi Suzuki, Chiayee Steve Chang, Lionel Jacques Garin, Ashutosh Pande
  • Patent number: 6462708
    Abstract: The present invention discloses a GPS system that uses call-processor intelligence to determine the mode of operation of a GPS receiver located in a GPS terminal. The modes are selected based on the availability of network facilities, the GPS information that can be acquired, or user input requirements.
    Type: Grant
    Filed: April 5, 2001
    Date of Patent: October 8, 2002
    Assignees: Sirf Technology, Inc., Matsushita Electric Works, Ltd.
    Inventors: Ikuo Tsujimoto, Junichi Suzuki, Chiayee Steve Chang, Lionel Jacques Garin, Ashutosh Pande