Abstract: An apparatus for processing spread spectrum signals is disclosed. The apparatus includes an intermediate frequency (IF) signal preprocessing unit, which includes a first set of multiply-accumulator (MAC) units and a second set of MAC units. The IF signal preprocessing unit generates a first and a second set of data streams using a digitized signal and a first and second local reference signals respectively. Each data stream is generated every predetermined time period, and each data stream includes pre-integration results generated at a predetermined rate.

Abstract: A positioning method using global positioning system (GPS) signal and digital broadcasting system (DBS) signal. The method includes detecting a presence status of the GPS signal through a signal detector in a receiver, detecting a presence status of the DBS signal through the signal detector, determining the signal strength of the GPS signal if the GPS signal is detected, determining the signal strength of the DBS signal if the DBS signal is detected, choosing one positioning mode among a plurality of positioning modes in a signal processing unit in the receiver based on signal presence status and the signal strength of a detected signal, and determining a location of the receiver based on the chosen positioning mode. The plurality of positioning modes includes standalone GPS mode, assisted GPS (AGPS) mode, assisted GPS positioning with DBS assist mode, DBS positioning with GPS assist mode, standalone DBS mode, and assist DBS mode.

Abstract: A Global Positioning System (GPS) system includes multiple GPS application servers. The multiple GPS application servers provide GPS assistant information for locating a mobile terminal. The mobile terminal receives GPS information from multiple GPS satellites. The GPS assistant information is determined based on a GPS position and a geographic position of a GPS application server of the multiple GPS application servers. The GPS application server is nearest of the multiple GPS application servers to the mobile terminal, and the geographic position of the GPS application server is known.

Abstract: A positioning method using global positioning system (GPS) signal and digital broadcasting system (DBS) signal. The method includes detecting a presence status of the GPS signal through a signal detector in a receiver, detecting a presence status of the DBS signal through the signal detector, determining the signal strength of the GPS signal if the GPS signal is detected, determining the signal strength of the DBS signal if the DBS signal is detected, choosing one positioning mode among a plurality of positioning modes in a signal processing unit in the receiver based on signal presence status and the signal strength of a detected signal, and determining a location of the receiver based on the chosen positioning mode. The plurality of positioning modes includes standalone GPS mode, assisted GPS (AGPS) mode, assisted GPS positioning with DBS assist mode, DBS positioning with GPS assist mode, standalone DBS mode, and assist DBS mode.

Abstract: The present invention is a method for GPS positioning in a weak signal environment. The method includes obtaining assistance data for a GPS signal from a satellite at a predetermined time, wherein the assistance data including predicted navigation data, Doppler shift and Doppler shift rate and the GPS signal being modulated by a carrier signal, a pseudorandom code and navigation data, estimating a predicted receiving time for the GPS signal reaching the GPS receiver, capturing the GPS signal, converting the GPS signal to an intermediate frequency signal, acquiring a code phase of the pseudorandom code from the intermediate frequency signal by using the assistance data and the predicted receiving time, and obtaining a position for the GPS receiver based on the predicted navigation data and the code phase of the pseudorandom code.

Abstract: A positioning method using global positioning system (GPS) signal and digital broadcasting system (DBS) signal. The method includes detecting a presence status of the GPS signal through a signal detector in a receiver, detecting a presence status of the DBS signal through the signal detector, determining the signal strength of the GPS signal if the GPS signal is detected, determining the signal strength of the DBS signal if the DBS signal is detected, choosing one positioning mode among a plurality of positioning modes in a signal processing unit in the receiver based on signal presence status and the signal strength of a detected signal, and determining a location of the receiver based on the chosen positioning mode. The plurality of positioning modes includes stand-alone GPS mode, assisted GPS (AGPS) mode, assisted GPS positioning with DBS assist mode, DBS positioning with GPS assist mode, stand-alone DBS mode, and assist DBS mode.

Abstract: A method for estimating signal quality of a spread spectrum signal is provided. The method includes squaring a plurality of in-phase correlation results and a plurality of quadrature correlation results, summing each squared in-phase correlation result and the corresponding correlation result to obtain a plurality of sum-of-square values, detecting a peak value among the plurality of sum-of-square results, calculating an average of non-peak values among the plurality of sum-of-square results. The peak value is regarded as a signal power value, while the averaged non-peak values are regarded as an average noise power value. A signal-to-noise ratio is then calculated based on the signal power value and the average noise power value. A method for determining the parameters for the tracking loop is also provided. The method includes estimating the signal-to-noise ratio of the spread spectrum signal, and determining the tracking loop parameters based on the signal-to-noise ratio.

Abstract: An apparatus for processing spread spectrum signals is disclosed. The apparatus includes an intermediate frequency (IF) signal preprocessing unit, which includes a first set of multiply-accumulator (MAC) units and a second set of MAC units. The IF signal preprocessing unit generates a first and a second set of data streams using a digitized signal and a first and second local reference signals respectively. Each data stream is generated every predetermined time period, and each data stream includes pre-integration results generated at a predetermined rate.

Abstract: An apparatus for processing spread spectrum signals digitized at a predetermined sampling frequency. The apparatus includes an intermediate frequency signal preprocessing unit, a plurality of parallel block integrators. The intermediate frequency signal preprocessing unit is capable of generating pre-integration results based on an input signal and local reference signals at a predetermined rate. The pre-integration results produced by the intermediate frequency signal preprocessing unit are grouped into sets of pre-integration results. Each set of the pre-integration results contains a predetermined number of pre-integration results. The plurality of parallel block integrators is in communication with the intermediate frequency signal preprocessing unit.

Abstract: A method for processing spread spectrum signals through a two step integration process in a circuit having an intermediate frequency signal preprocessing unit and a plurality of block integrators, wherein the circuit receiving a digitized signal, a local reference signal, and a pseudorandom noise code. The method includes generating a plurality of data streams by the intermediate frequency signal preprocessing unit using the digitized signal and the reference signal, receiving at each block integrator a data stream from the plurality of data streams and the pseudorandom noise code, performing a predetermined number of partial correlations at each block integrator using hybrid correlation technique based on the data stream and the pseudorandom noise code to obtain a predetermined number of partial correlation results, and computing a predetermined number of complete correlation results based on the predetermined number of partial correlation results.

Abstract: A method for estimating signal quality of a spread spectrum signal is provided. The method includes squaring a plurality of in-phase correlation results and a plurality of quadrature correlation results, summing each squared in-phase correlation result and the corresponding correlation result to obtain a plurality of sum-of-square values, detecting a peak value among the plurality of sum-of-square results, calculating an average of non-peak values among the plurality of sum-of-square results. The peak value is regarded as a signal power value, while the averaged non-peak values are regarded as an average noise power value. A signal-to-noise ratio is then calculated based on the signal power value and the average noise power value. A method for determining the parameters for the tracking loop is also provided. The method includes estimating the signal-to-noise ratio of the spread spectrum signal, and determining the tracking loop parameters based on the signal-to-noise ratio.

Abstract: The present invention is a method for GPS positioning in a weak signal environment. The method includes obtaining assistance data for a GPS signal from a satellite at a predetermined time, wherein the assistance data including predicted navigation data, Doppler shift and Doppler shift rate and the GPS signal being modulated by a carrier signal, a pseudorandom code and navigation data, estimating a predicted receiving time for the GPS signal reaching the GPS receiver, capturing the GPS signal, converting the GPS signal to an intermediate frequency signal, acquiring a code phase of the pseudorandom code from the intermediate frequency signal by using the assistance data and the predicted receiving time, and obtaining a position for the GPS receiver based on the predicted navigation data and the code phase of the pseudorandom code.

Abstract: A positioning method using global positioning system (GPS) signal and digital broadcasting system (DBS) signal. The method includes detecting a presence status of the GPS signal through a signal detector in a receiver, detecting a presence status of the DBS signal through the signal detector, determining the signal strength of the GPS signal if the GPS signal is detected, determining the signal strength of the DBS signal if the DBS signal is detected, choosing one positioning mode among a plurality of positioning modes in a signal processing unit in the receiver based on signal presence status and the signal strength of a detected signal, and determining a location of the receiver based on the chosen positioning mode. The plurality of positioning modes includes stand-alone GPS mode, assisted GPS (AGPS) mode, assisted GPS positioning with DBS assist mode, DBS positioning with GPS assist mode, stand-alone DBS mode, and assist DBS mode.

Abstract: A Global Positioning System (GPS) system comprises a user end, a mobile terminal, a positioning server, a GPS application server, and a base station network. The mobile terminal has a GPS receiver to receive GPS information from a plurality of GPS satellites. The positioning server is coupled to the user end through the network. The GPS application server is coupled to the network for communicating with the positioning server, and has a GPS receiver to receive GPS information from GPS satellites so as to calculate a position of the GPS application server. The geographic position of the GPS application server is known, and GPS assistant information is determined based on the calculated position and the geographic position of the GPS application server. The base station network communicates with the mobile terminal to obtain the GPS information of the mobile terminal and locate the mobile terminal based on the GPS information of the mobile terminal and the GPS assistant information.

Abstract: A method for processing spread spectrum signals through a two step integration process in a circuit having an intermediate frequency signal preprocessing unit and a plurality of block integrators, wherein the circuit receiving a digitized signal, a local reference signal, and a pseudorandom noise code. The method includes generating a plurality of data streams by the intermediate frequency signal preprocessing unit using the digitized signal and the reference signal, receiving at each block integrator a data stream from the plurality of data streams and the pseudorandom noise code, performing a predetermined number of partial correlations at each block integrator using hybrid correlation technique based on the data stream and the pseudorandom noise code to obtain a predetermined number of partial correlation results, and computing a predetermined number of complete correlation results based on the predetermined number of partial correlation results.

Abstract: An apparatus for processing spread spectrum signals digitized at a predetermined sampling frequency. The apparatus includes an intermediate frequency signal preprocessing unit, a plurality of parallel block integrators. The intermediate frequency signal preprocessing unit is capable of generating pre-integration results based on an input signal and local reference signals at a predetermined rate. The pre-integration results Produced by the intermediate frequency signal preprocessing unit are grouped into sets of pre-integration results. Each set of the pre-integration results contains a predetermined number of pre-integration results. The plurality of parallel block integrators is in communication with the intermediate frequency signal preprocessing unit.