摘要:
A method and apparatus for performing frequency analysis of sub-epoch correlations to estimate an unknown frequency of a received signal is provided. The method includes forming a sequence of correlation values from a plurality of correlations performed over a period less than a repeating period of a code, and analyzing the sequence of correlation values to estimate the frequency that is used to receive a signal comprising the code.
摘要:
A method and apparatus for locating position of a satellite signal receiver is described. In one example, groups of pseudoranges from the satellite signal receiver to a plurality of satellites are determined at a respective plurality of times. The groups of pseudoranges are transmitted to a server, where a position of the satellite signal receiver may be determined using the groups of pseudoranges. In another example, a plurality of groups of pseudoranges are applied to a time-based filter located in the server. The position of the satellite signal receiver is derived from the time-based filter.
摘要:
A method and apparatus for using a conventional oscillator in a cellular telephone transceiver as a source of a reference signal for a GPS receiver. In one embodiment, the method comprises using a voltage-controlled oscillator (nullVCXOnull) within a cellular telephone transceiver to generate a reference frequency signal for the GPS receiver. Circuitry within the telephone transceiver generates a frequency error signal. Both of these signals are coupled to GPS circuitry and used to control a carrier numerically controlled oscillator (nullNCOnull) and a code NCO. The NCOs produce a tuning signal and a timing signal, respectively. The GPS circuitry uses the NCO generated signals to process GPS signals.
摘要:
A method and apparatus for providing location-based information using a wireless communications system is disclosed. In one embodiment, a message is received from a wireless device containing a request for location-based information. Upon receipt of the message, the location of the wireless device is determined, location-based information is retrieved for the determined location and the location-based information is transmitted to the wireless device.
摘要:
A method and apparatus for mitigating interference in a satellite signal receiver is described. The satellite signal receiver receives satellite signals from a plurality of satellites. In one example a control signal is transmitted to the satellite signal receiver upon occurrence of data transmission from a wireless transceiver operating in proximity to the satellite signal receiver. Signal integration within the satellite signal receiver is gated in response to the control signal In another example, one or more values of satellite signal samples are selected from a plurality of possible values. Signal integration within the satellite signal receiver is gated in response to a percentage of satellite signal samples taken over a predefined period exceeding a predefined threshold. In yet another example, a gain setting of an automatic gain control circuit within the satellite signal receiver is adjusted in response to detection of interference.
摘要:
A method and apparatus for distribution and delivery of global positioning system (GPS) satellite telemetry data using a communication link between a central site and a mobile GPS receiver. The central site is coupled to a network of reference satellite receivers that send telemetry data from all satellites to the central site. The mobile GPS receiver uses the delivered telemetry data to aid its acquisition of the GPS satellite signal. The availability of the satellite telemetry data enhances the mobile receiver's signal reception sensitivity.
摘要:
Method and apparatus for using long term satellite tracking data in a remote receiver is described. In one example, long term satellite tracking data is received at a remote receiver from a server. The long term satellite tracking data is used to compute acquisition assistance data in the remote receiver. The remote receiver then uses the acquisition assistance data to acquire satellite signals. The acquired satellite signals may be used to locate position of the remote receiver.
摘要:
A method and apparatus for correlating a satellite signal with a reference code is described. In an example, samples of a satellite signal having a repeating code are received. At least one fast convolution between the samples and the pseudorandom reference code is performed. A correlation peak is detected within a result of the at least one fast convolution. A code phase of the repeating code relative to the pseudorandom reference code is estimated at the correlation peak. The samples are then correlated with the pseudorandom reference code using the code phase as an initial value.
摘要:
A method and apparatus for performing timing synchronization in a mobile device. The method and apparatus include a wireless transceiver having a first oscillatory signal generator (OSG) and a Global Position System (GPS) receiver. The GPS receiver includes a second oscillatory signal generator coupled to a counter for receiving a first clock signal from the first OSG and a second clock signal from the second OSG. Additionally, a GPS signal processor is coupled to the counter. The counter provides a relative offset signal between the first and second oscillatory signal generators to the GPS signal processor for adjusting a pseudo-range model.
摘要:
A method and apparatus for computing a convolution between an input GPS signal and a C/A code reference by generating the convolution result in real time without storing unprocessed signal samples. The apparatus comprises a vector multiplier running at high speed to achieve the same result as a vector multiplier sized to process an entire epoch.