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: Methods and apparatuses to obtain an ordered set of satellite positioning system (SPS) satellites, in view of a mobile SPS receiver, via one or two-way communication with the mobile SPS receiver. The mobile SPS receiver receives, in one embodiment, an ordered set of SPS satellites from a cellular transmission site. The ordered set of satellites are those in view of the mobile SPS receiver at a given time; such that the mobile SPS receiver may search for the SPS satellites according to an order of the ordered set of SPS satellites. The order of the ordered set may be obtained by various methods one of which is by minimizing the geometric dilution of precision (GDOP) Satellite; health data may be included in the transmission.

Abstract: Techniques to estimate the velocity of a terminal in a wireless communication system. Movement by the terminal results in a Doppler shift in the frequency of each transmitted signal received at the terminal. In one method, the positions of the terminal, a base station, and each of two or more satellites are initially determined. A residual rate of change of pseudo-range may also be determined for each satellite, e.g., based on (1) an estimated baseband frequency error that includes the Doppler frequency shift due to the terminal's movement and (2) an estimated Doppler frequency shift due to movement by the satellite. A set of equations is then formed based on the determined positions of the terminal, the base station, and the satellites and the determined residual rates of change of pseudo-ranges for the satellites. The velocity of the terminal may thereafter be estimated based on the set of equations.

Abstract: Corrections to a coarse position estimate of the pseudorange receiving device are made based upon knowledge of the amount of error present in inaccurate information (e.g., the old Almanac and/or Ephemeris) used to estimate the coarse position.

Abstract: A spread spectrum wireless device (100) may include a receiver (110), a searcher (128), a search controller (130) and other features. The search controller (130) selectively generates control signals to control the searcher (128), which searches for a spread-spectrum signal. In one embodiment, the architecture of the searcher (128) is dynamically configurable by the search controller (130) to selectively search multiple channels using multiple frequency bins for the signal.

Abstract: A method for estimating the earliest signal arrival in a wireless communication system is presented. The system includes a base station that transmits a plurality of pilot signals and a mobile station configured to receive a plurality of signals corresponding to the pilot signals. The mobile station includes a receiver containing a searcher correlation mechanism and at least one finger correlation mechanism. The mobile station receiver detects the arrival times and energy levels of the received signals and constructs a searcher histogram and a finger histogram associated with each pilot signal. Each of the searcher and finger histograms represents an arrival time distribution of samples corresponding to the received signals. The mobile station receiver processes samples contained within each of the searcher histograms and the finger histograms to generate a plurality of estimated early signal arrivals. The earliest signal arrival is determined from the plurality of estimated early signal arrivals.

Abstract: A method and apparatus for performing on-going calibration of a communication system in which a master system unit is coupled to one or more remote units via a relatively long wireline. On the forward link, measurements are made of at the input to the master system unit and the output of each remote unit. On the reverse link, the input to the remote unit is and the output from the master unit is measured when there is a dominant signal applied to one of the remote units. These measurements are made for a controlled signal during an initialization process and during normal operation. A reference gain for the system is determined from the measurements made during initialization. The gain of the system during normal operation is then dynamically compared to the reference gain of the system. A control signal is generated based on the difference between the reference gain and the current gain under normal operation.

Abstract: A method of performing duty cycle correction of an input signal having a non-uniform duty cycle is provided. A signal representative of the difference in duration between the positive and negative portions of the input signal duty cycle is formed. A switching level is derived from the signal. An output signal is then formed through a switching action, whereby durations of positive and negative portions of the output signal duty cycle are defined by crossover points between the input signal and the switching level. The signal (and switching level) are adjusted, if necessary, until the output signal duty cycle is at least substantially uniform.

Abstract: A system and method for dynamically calibrating a base station in a wireless communication system, is presented herein. In accordance with an embodiment of the invention, the system includes a base station for transmitting, receiving, and processing communication signals and a wireless communication device for communicating with the base station. The wireless communication device is configured to determine its location (e.g., using GPS information), to detect the arrival time of a first signal transmitted from the base station, and to calculate a line-of-sight (LOS) delay corresponding to the LOS distance between the wireless communication device and the base station. The LOS distance calculation is based on the base station location information and the wireless communication device location information.

Abstract: Method and apparatus for subsampling phase spectrum information by analyzing and reconstructing a prototype of a frame. The prototype is analyzed by correlating phase parameters generated from the prototype with phase parameters generated from a reference prototype in multiple frequency bands. The prototype is reconstructed using linear phase shift values by producing a set of phase parameters of the reference prototype, generating a set of linear phase shift values associated with the prototype, and composing a phase vector from the set of phase parameters and the set of linear phase shift values across multiple frequency bands. The prototype is reconstructed using circular rotation values by producing a set of circular rotation values associated with the prototype, generating a set of bandpass waveforms associated with the phase parameters of the reference prototype in multiple frequency bands, and modifying the set of bandpass waveforms based upon the circular rotation values.

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 confirming the identity of a mobile station in a communication network. A mobile station transmits a security value to obtain access to the network. The system authenticates the mobile station prior to granting it access to the network. The system performs an additional procedure before granting access to the system if the security value sent by the mobile station matches a previously transmitted security value. Using this invention, the system prevents attempts of replay attacks by intruders.

Abstract: The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. One embodiment of the invention comprises a method of performing position location in a wireless subscriber unit having a local oscillator, including the steps of receiving a position location request, acquiring a timing signal when a sufficient period of time has elapsed since the local oscillator has been corrected and correcting the local oscillator using a correction signal based on the timing signal, substantially freezing the correction signal, performing a position location procedure using the local oscillator with the correction signal applied, and ending said position location procedure.

Abstract: An efficient turbo decoder. The disclosed turbo decoder includes a first mode of operation in which the turbo decoder uses a first functional loop. The first functional loop includes a memory bank, a read interleaver, a first multiplexer (MUX), a RAM file, a log-MAP decoder, a write interleaver, and a second MUX. The disclosed turbo decoder further includes a second mode of operation in which a second functional loop is used. The second functional loop includes the memory bank, the first MUX, the RAM file, the log-MAP decoder, and the second MUX. The memory bank is a dual port extrinsic memory. The disclosed turbo decoder circuit switches between the first mode and the second mode.

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: A system and method for selecting from a plurality of data service options in a wireless communication network is presented. The system includes a terminal device for originating a call and for transmitting and receiving data in accordance with a selected data service option. The terminal device includes a dialing interface for inputting a sequence of one or more symbols representing a dial command string for originating the call. The input symbol sequence includes information indicating the selection of a data service option. The system also includes a communication device, coupled to the terminal device, for receiving the dial command string from the terminal device, for storing a plurality of pre-determined symbol sequences including standard telephone numbers and reserved telephone number sequences representing different data service options, and for comparing the contents of the dial command string with the stored pre-determined symbol sequences.

Abstract: The disclosed embodiments provide a method and apparatus for interoperability between CTX and DTX communications systems during transmissions of silence or background noise. Continuous eighth rate encoded noise frames are translated to discontinuous SID frames for transmission to DTX systems. Discontinuous SID frames are translated to continuous eighth rate encoded noise frames for decoding by a CTX system.

Abstract: A method and apparatus whereby a remote unit in a slotted mode wireless communication system may calculate accurate time throughout its entire active state. In the remote unit a “wall clock time” is calculated from a modulo 80 counter called a combiner time counter. When a remote unit enters its inactive state, counters within the remote unit, including the combined time counter, are deactivated. When the remote unit reenters its active state, the value in the combiner time counter may not be correct in relationship to slotted mode time. A controller in the remote unit forces the combiner time counted to the correct phase resulting in the combiner being within 26.66 of the correct value. The controller then determines a combiner offset to compensate for any remaining error in the combiner time counter. The control may then use the combiner time counter and the combiner offset to calculate accurate wall clock time.

Abstract: An arrangement for protecting an element from electro-static discharge. A switch is provided to inhibit the flow of energy through the element in response to the control signal. In the illustrative embodiment, the switch is a transistor switch. A resistor is disposed between an input terminal of the transistor and the positive supply to keep the transistor on during normal operation. A capacitor is disposed between the input terminal of the transistor and ground to prevent the input voltage of the transistor from fast changing. The RC time constant is chosen to be much larger than the time constant of the ESD pulse. Consequently, input voltage of the transistor will remain unchanged near ØV and the transistor will remain off during ESD event preventing the element from conducting the discharge current and providing ESD protection.

Abstract: A method for allocating blocks within sectored EEPROM (commonly referred to as flash memory) based memory to minimize data relocation overhead and maximize sectored EEPROM lifetime. Data to be saved within sectored EEPROM is configured into data pages or blocks representing the minimum data size that is relocated within the sectored EEPROM in any given erase cycle. Multiple data blocks are contained within a single sector. A sector represents the minimum data size that is erased from the sectored EEPROM in any single erase cycle. Each block has a corresponding calculated value of volatility and new or updated data blocks to be added to the file are saved in sectored EEPROM according to a hierarchy based upon the calculated volatility of the data block. Data blocks with a calculated volatility within a predetermined threshold of the average volatility of a sector are saved within the most occupied sector containing no obsolete blocks.