Abstract: A method and apparatus for determining a reference time associated with a satellite positioning system. In turn, the reference time, in one embodiment, may be used to determine other navigational information. Such navigational information may include, for example, the location/position of a satellite positioning system (SPS) receiver. In one embodiment, a relative velocity between an SPS receiver and a set of one or more satellites is used to determine an offset between time as indicated by the SPS receiver and the reference time. According to another embodiment of the invention, an error statistic is used to determine the reference time. According to yet another embodiment of the invention, two records, each representing at least a portion of a satellite message, are compared to determine time. In one implementation, the SPS receiver is mobile and operates in conjunction with a basestation to determine time and/or other navigational information according to one or a combination of the methods described.

Abstract: Methods and apparatuses for distributing location-based information (i.e., information specific to a client's location or a location of interest to the client) to a client, which may be a mobile SPS receiver, via the Internet and in particular, the World-Wide Web. The client provides information about its location and/or a location of interest to a Web server. The Web server, based on the information, provides via the Internet information relating to the client's location or location of interest to the client.

Abstract: A method and apparatus for determining a reference time associated with a satellite positioning system. In turn, the reference time, in one embodiment, may be used to determine other navigational information. Such navigational information may include, for example, the location/position of a satellite positioning system (SPS) receiver. In one embodiment, a relative velocity between an SPS receiver and a set of one or more satellites is used to determine an offset between time as indicated by the SPS receiver and the reference time. According to another embodiment of the invention, an error statistic is used to determine the reference time. According to yet another embodiment of the invention, two records, each representing at least a portion of a satellite message, are compared to determine time. In one implementation, the SPS receiver is mobile and operates in conjunction with a basestation to determine time and/or other navigational information according to one or a combination of the methods described.

Abstract: A method and apparatus of determining the time for a global positioning system receiver is disclosed. Timing signals derived from a communication system, such as cellular phone transmission signals, are received by a GPS receiver and decoded to provide accurate time information. The timing signals may be in the form of synchronized events marked by timing indicators, or as system time information. The timing signals in combination with satellite position signals received by the GPS receiver are used to determine the position of the GPS receiver.

Abstract: Methods and apparatuses for deriving an approximate Doppler for a satellite positioning system (SPS) receiver from an approximate location which is obtained from a cellular communication system information source. In one embodiment, an approximate location of the SPS receiver is derived from the information source and this approximation location is used to determine approximate Dopplers to a plurality of SPS satellites at a given time. The approximate Dopplers are then used to reduce processing time in either determining pseudoranges to the SPS satellites or acquiring signals from the SPS satellites. In another aspect of the invention, a reference signal is used to provide a local oscillator signal which is used to acquire SPS signals in an SPS receiver. This reference signal is extracted from a data signal modulated on a carrier frequency.

Abstract: Method and apparatuses for receiving and tracking satellite signals in a highly sensitive and accurate receiver. In one aspect of the invention an exemplary method includes generating a set of at least three indicators based on processing a portion of a satellite positioning system signal received by a receiver and computing a measurement of a parameter from an interpolation of the set of indicators. Each of the indicators corresponds to a different predetermined hypothesized value of the parameter and is indicative of a probability, or likelihood, that the parameter of the signal is equal to that corresponding value.

Abstract: Methods and apparatuses which use satellite position system (SPS) reference receivers. In one example of the invention, a plurality of SPS reference receivers, such as Global Positioning System (GPS) reference receivers, each having a known position, are dispersed over a geographical region. Each of the SPS reference receivers transmits into a communication network, a representation of at least a portion of a satellite navigation message, such as satellite ephemeris data, received from SPS satellites in view of the particular SPS reference receiver. A plurality of digital processing systems, such as a first and a second digital processing systems, are coupled to the communication network to receive the satellite ephemeris data which is transmitted through the communication network.

Abstract: A precision carrier frequency signal for calibrating a local oscillator of a GPS receiver which is used to acquire GPS signals. The precision carrier frequency signal is used to calibrate the local oscillator such that the output of the local oscillator, which is used to acquire GPS signals, is modified by a reference signal generated from the precision carrier frequency signal. The GPS receiver locks to this precision carrier frequency signal and generates the reference signal. In another aspect of the invention, satellite almanac data is transmitted to a remote GPS receiver unit from a basestation via a communication link. The remote GPS receiver unit uses this satellite almanac data to determine approximate Doppler data for satellites in view of the remote GPS receiver unit.

Abstract: A method and apparatus is disclosed for measurement processing of Satellite Positioning System (SPS) signals. A plurality of SPS signals from a corresponding plurality of SPS satellites are received in an SPS receiver. The signal environment corresponding to the location in which the SPS receiver is located is characterized to produce signal environment data. In one exemplary embodiment, an information source, such as a cellular network based database, is searched to retrieve the signal environment data given an approximate location of the GPS receiver. This approximate location may be specified by a location of a cell site which is in cellular radio communication with a cellular communication device which is co-located with the GPS receiver. One or more parameters related to signal characteristics of the satellite signals are defined. Threshold values for the parameters are determined using the signal environment data.

Abstract: A method and apparatus for measuring time related to satellite data messages which are used with satellite positioning systems (SPS). In one method, a first record of at least a portion of a satellite data message is received at an entity, which is typically a basestation. The first record is compared with a second record of the satellite data message, where the first record and the second record overlap at least partially in time. Then a time is determined from this comparison, and this time indicates when the first record (or the source from which the first record was obtained) was received at a remote entity which is typically a mobile SPS receiver. Various other methods of the invention are described and various apparatuses of the invention are also described. The methods and apparatuses measure time of day using SPS signals without reading the satellite data messages which are transmitted as data within these signals.

Abstract: A global positioning system (GPS) receiver has first circuitry for receiving and processing pseudorandom sequences transmitted by a number of GPS satellites. The first circuitry is configured to perform conventional correlation operations on the received pseudorandom sequences to determine pseudoranges from the GPS receiver to the GPS satellites. The GPS receiver also includes second circuitry coupled to the first circuitry. The second circuitry is configured to receive and process the pseudorandom sequences during blockage conditions. The second circuitry processes the pseudorandom sequences by digitizing and storing a predetermined record length of the received sequences and then performing fast convolution operations on the stored data to determine the pseudoranges. The GPS receiver may have a common circuitry for receiving GPS signals from in view satellites and downconverting the RF frequency of the received GPS signals to an intermediate frequency (IF).

Abstract: A method and apparatus for measuring time related to satellite data messages which are used with satellite positioning systems (SPS). In one method, a first record of at least a portion of a satellite data message is received at an entity, which is typically a basestation. The first record is compared with a second record of the satellite data message, where the first record and the second record overlap at least partially in time. Then a time is determined from this comparison, and this time indicates when the first record (or the source from which the first record was obtained) was received at a remote entity which is typically a mobile SPS receiver. Various other methods of the invention are described and various apparatuses of the invention are also described. The methods and apparatuses measure time of day using SPS signals without reading the satellite data messages which are transmitted as data within these signals.

Abstract: Methods and apparatuses which use satellite position system (SPS) reference receivers. In one example of the invention, a plurality of SPS reference receivers, such as Global Positioning System (GPS) reference receivers, each having a known position, are dispersed over a geographical region. Each of the SPS reference receivers transmits into a communication network, a representation of at least a portion of a satellite navigation message, such as satellite ephemeris data, received from SPS satellites in view of the particular SPS reference receiver. A plurality of digital processing systems, such as a first and a second digital processing systems, are coupled to the communication network to receive the satellite ephemeris data which is transmitted through the communication network.

Abstract: A method and apparatus is disclosed for measurement processing of Satellite Positioning System (SPS) signals. A plurality of SPS signals from a corresponding plurality of SPS satellites are received in an SPS receiver. The signal environment corresponding to the location in which the SPS receiver is located is characterized to produce signal environment data. In one exemplary embodiment, an information source, such as a cellular network based database, is searched to retrieve the signal environment data given an approximate location of the GPS receiver. This approximate location may be specified by a location of a cell site which is in cellular radio communication with a cellular communication device which is co-located with the GPS receiver. One or more parameters related to signal characteristics of the satellite signals are defined. Threshold values for the parameters are determined using the signal environment data.

Abstract: Methods and apparatuses for deriving an approximate Doppler for a satellite positioning system (SPS) receiver from an approximate location which is obtained from a cellular communication system information source. In one embodiment, an approximate location of the SPS receiver is derived from the information source and this approximation location is used to determine approximate Dopplers to a plurality of SPS satellites at a given time. The approximate Dopplers are then used to reduce processing time in either determining pseudoranges to the SPS satellites or acquiring signals from the SPS satellites. In another aspect of the invention, a reference signal is used to provide a local oscillator signal which is used to acquire SPS signals in an SPS receiver. This reference signal is extracted from a data signal modulated on a carrier frequency.

Abstract: A hybrid fiber/coax digital data transmission system in which data from a plurality of subscribers are transmitted upstream to a headend demodulator in a series of data bursts. The headend demodulator acquires and synchronizes a data burst by detecting a BPSK preamble having a repetitive one and zero pattern (10101010101000). The pattern is detected by integrating clock energy in an envelope of a preamble length transmission and using the last three symbols (0,0,0) as a frame marker after differential decoding. Noise in the system is periodically measured by detecting an empty burst placed periodically in the data stream. A first-in, first-out (FIFO) memory allows closer spacing for the data bursts by permitting asynchronous received and output clocks.

Abstract: A method and apparatus of acquiring and tracking global positioning system signals with fast acquisition speed and high sensitivity is disclosed. A pseudo-random noise matching filter operation is performed on a sample of global positioning system signals to provide a current matched filter result. The current matched filter result is then accumulated with a prior matched filter result from a prior sample of global positioning system signals to produce an accumulated matched filter result. Efficient means for implementing the matched filter are disclosed.

Abstract: A method and apparatus for receiving and processing burst-mode code-division multiple access (CDMA) direct-sequence spread-spectrum (DSSS) signals is provided. In this apparatus and method, a number of demodulators are provided in a set enumerated order. Each demodulator is either “ready,” meaning that it is free to process signals, or busy meaning that it is currently processing a signal. The ready demodulators each receive an input IF signal and try to detect a preamble in the IF signal. Once they detect the preamble, each ready demodulator then sends a request signal to an arbitrator. In response to a received request signal, the arbitrator sends a grant signal to the first ready demodulator in the enumerated order. This grant signal passes through each busy demodulator that is higher in the enumerated order than the first ready demodulator. The first ready demodulator then begins processing the signal, and is moved from the set of ready demodulators to the set of busy demodulators.

Abstract: A global positioning system (GPS) receiver has first circuitry for receiving and processing pseudorandom sequences transmitted by a number of GPS satellites. The first circuitry is configured to perform conventional correlation operations on the received pseudorandom sequences to determine pseudoranges from the GPS receiver to the GPS satellites. The GPS receiver also includes second circuitry coupled to the first circuitry. The second circuitry is configured to receive and process the pseudorandom sequences during blockage conditions. The second circuitry processes the pseudorandom sequences by digitizing and storing a predetermined record length of the received sequences and then performing fast convolution operations on the stored data to determine the pseudoranges. The GPS receiver may have a common circuitry for receiving GPS signals from in view satellites and downconverting the RF frequency of the received GPS signals to an intermediate frequency (IF).

Abstract: A GPS receiver having multiple GPS antennas. Also described is a method of tracking employing the GPS receiver and a communication transmitter. Also described is a garment having a GPS receiver and a GPS antenna and a communication antenna and a communication transmitter.