Abstract: A tunable oscillator having a tuning voltage input includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. The first varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range.

Abstract: A method and apparatus to perform position determination in a wireless (e.g., cellular) communication network with repeaters. A signal received by a terminal is initially identified as being from a repeater. A position and a position uncertainty for the identified repeater are obtained (e.g., from a repeater database) and provided as the position estimate and position uncertainty for the terminal if (1) a more accurate position estimate for the terminal cannot be obtained, (2) the terminal is deemed to be in an indoor environment, or (3) the terminal is located sufficiently close to the identified repeater. If information for additional delays associated with the identified repeater is available, then the position estimate for the terminal may be derived based on a “compensated” time measurement for the identified repeater (i.e., with the additional delays removed) and time measurements for at least two other transmitters received by the terminal.

Abstract: A system and method for adjusting loop bandwidth in a synchronization loop of a radio receiver uses a noncoherent peak detector to determine the maximum magnitude and timing of incoming data at various code phase offsets. The maximum magnitude and timing are used in subsequent processing with the maximum magnitude value used to determine an adjustment factor. The timing information associated with the maximum signal value is used to despread the incoming signal. The despread incoming signal is subsequently scaled in accordance with the determined adjustment factor such that the input to the synchronization loop is scaled to produce the desired loop bandwidth.

Abstract: The present invention includes a cellular pilot signal detector or searcher for use in a cellular mobile communications unit. The signal detector uses a matched filter to detect a pilot signal transmitted from a cellular base station. The matched filter includes a plurality of taps and a plurality of delays located between adjacent taps. The signal components of a received digital signal are held on the taps of the matched filter by the delays. The matched filter compares the signal components of the received signal to an expected or searched for digital pattern. The matched filter puts out a relatively large signal if the received digital signal matches the expected digital pattern. The matched filter can also be used in parallel with a correlator.

Abstract: A method and an apparatus for quick retransmission of signals in a communication system are disclosed. A transmitting terminal, e.g., a base station, transmits signals in a form of packets to a receiving terminal, e.g., a subscriber station. The receiving terminal determines if the packet was intended for the receiving terminal, and if so, the receiving terminal demodulates the packet. The receiving terminal then computes a quality metric of the packet, and compares the computed quality metric with a quality metric contained in the packet. If the quality metrics match, the packet is declared correctly received, and is forwarded for further processing. If the quality metrics fail to match, the receiving terminal sends a request for retransmission of the packet. The transmitting terminal determines which packet needs to be retransmitted based on the request for retransmission. The transmitting terminal then schedules the packet for retransmission.

Abstract: Techniques to reduce transmit power required for transmission of messages from an access terminal to reduce interference to transmissions from other access terminals. In one aspect, messages to be transmitted are defined and/or coded such that they may be detected at different received signal qualities. The codewords may be defined having different distances to their nearest codewords. In another aspect, messages to be transmitted are assigned to different points in a signal constellation, with the points being located such that they may be received at different signal qualities. Codewords that may be received at a lower signal quality may be assigned to messages more likely to be transmitted at higher transmit power levels (e.g., when the access terminal is located further away) or to more frequently transmitted messages.

Abstract: A system and method for bad frame indication of a speech frame includes estimating a signal-to-noise ratio (SNR) and checking a cyclic redundancy code (CRC) value of the speech frame. When the speech frame fails CRC error detection or the SNR is below a pre-specified value, a bad frame indication (BFI) flag is set. When the speech frame passes CRC error detection and the SNR is above the pre-specified value, a receive signal quality metric of the speech frame is checked against a high threshold and, if need be, a low threshold. The BFI flag and the receive signal quality metric for the previous speech frame is checked when the current receive signal quality metric is between the high and low thresholds. The BFI flag is set according to the value of the SNR, the CRC value, the current and previous receive signal quality metrics, and the previous BFI flag.

Abstract: A method of and system for detecting whether a peak of a correlation function derived from a received signal is due to a jammer. The peak is within a localized portion of the correlation function which has a total number of peaks. In one embodiment, the total number of peaks is compared to a threshold number of peaks, and the peak is identified as being due to a jammer if the total number of peaks equals or exceeds a threshold number of peaks. In a second embodiment, the peak energy in relation to a noise estimate for the localized portion of the correlation function is compared to a jammer threshold. The peak is identified as being due to a jammer if the peak energy in relation to the noise estimate is less than or equal to the jammer threshold.

Abstract: In a wireless communication network, base station antenna positions and time offsets are stored in a base station almanac data base along with other information used for obtaining the most reliable mobile station position fixes under a variety of conditions. The system uses the position fixes of mobile stations and terrestrial ranging information to determine base station antenna positions and base station timing offsets. The base station antenna positions are determined during normal mobile station position determinations, in order to maintain and improve the antenna location data, and to correct for change or relocation of the base station antennas. It is possible to recover quickly from a loss of cell sector identity during relocation of a base station antenna, and to ensure accuracy of mobile station position determination based on ranging from the base stations, and rapid acquisition of position data from mobile stations having global satellite receivers.

Abstract: Techniques for efficient storage and retrieval of Preferred Roaming Lists are disclosed. In one aspect, PRL entries are stored in two tables. One table contains records that are common to two or more PRL entries. Another table stores any information that is unique to a PRL entry, as well as an indicator of which common record is associated with it. The common record is concatenated with the unique information to generate the uncompressed PRL entry. Various other aspects of the invention are also presented. These aspects have the benefit of reducing the memory requirements for storing a PRL. In addition, time required to download the compressed PRL is reduced.

Abstract: A method and apparatus for creating and using a base station almanac for position determination is described. The base station almanac includes a number of records, where each record can describe a sector or a transmitter (e.g., a base station or a repeater) in a wireless communication network. Each record includes a protocol type field that indicates the one or more protocols supported by the record (e.g., IS-801, J-STD-36, GSM, W-CDMA, and so on). Each record also includes a unique sector identifier for the sector/transmitter for each supported protocol, where each identifier is defined based on the associated protocol. A record may also include multiple maximum antenna ranges (MARs), where each MAR is associated with a respective reference power level. One of the multiple MARs can be selected for use for position determination depending on received signal strength. The base station almanac further includes other features.

Abstract: A transmitter directed, distributed receiver using path diversity provided by the distribution of the receiver. Advantage is taken of the uncorrelated variations over time in the condition of channels between a common transmitter and several users. The greater the variation in the channel condition of a particular channel over time, the greater the increase in total system throughput provided. An access metric represents the instantaneous channel condition of the communication system between each user and the transmitter with respect to the average channel condition of each channel. Alternatively, the access metric represents the instantaneous channel condition with respect to the average data throughput over that channel. The common transmitting station uses the access metric to directly compare the desirability of granting each channel access with the desirability of granting each other channel access. The user that has the greatest access metric is provided access to the channel.

Abstract: A VCO with temperature compensation is achieved using reverse biased diodes. The VCO includes an amplifier that provides the required signal gain, a resonator tank circuit that provides the required phase shift, and at least one frequency tuning circuit for tuning the frequency of the oscillator signal. Each frequency tuning circuit includes at least one tuning capacitor and at least one MOS pass transistor that connects or disconnects the tuning capacitor(s) to/from the resonator tank circuit. Each reverse biased diode may be a parasitic diode that is formed at a drain or source junction of a MOS transistor. The reverse biased diodes have capacitance that can be controlled by a reverse bias voltage to compensate for drift in the VCO oscillation frequency over temperature.

Abstract: The memory card is comprised of memory that stores a user name and password for each respective network address or universal resource locator (URL). The information is encrypted to preclude unauthorized access to the memory. A controller controls operation and access to the card. A bus interface couples the card to various buses, such as a universal serial bus. When the card is attached to an electronic device that is accessing a particular URL, the consumer enters the password or other unlock request information. Once the unlock request is validated, the user name and password associated with that particular URL is transmitted to the browser on the electronic device that is requesting the information.

Abstract: A variable impedance load (104) is provided at the output of a radio frequency (RF) driver amplifier (102) having a variable gain. In an exemplary embodiment, the variable load (104) comprises a resistor (R) in series with a semiconductor device (M1). The semiconductor device (M1) has an impedance level determined by a drive current. The value of the drive current is related to the gain of the RF driver amplifier (102).

Abstract: A radio frequency (RF) driver amplifier system and method that provides linear in decibel gain control is provided. The RF driver amplifier system comprises a linear transconductor receiving an input voltage and providing a controlled current based on input voltage received, temperature compensation circuitry for varying current from the linear transconductor according to absolute temperature, an exponential current controller receiving current varied according to temperature and providing an exponential current in response, and an inductive degeneration compensator receiving exponential current and providing a control current to driver amplifier circuitry, thereby compensating for inductive degeneration due to at least one inductor in the driver amplifier circuitry. Control current passes from the inductive degeneration compensator to the driver amplifier circuitry. Output gain from the driver amplifier circuitry varies linearly in decibels with respect to the input voltage.

Abstract: A novel method is disclosed for the allocation of the capacity of a common channel among a number of data producers. In this method, a producer's future allocation grant is based on the extent to which the producer has used a previous allocation grant. The method is applicable to any system wherein the simultaneous use of a common channel by more than one producer may cause a data collision, and an exemplary application to the reverse link of a CDMA telecommunications system is described. Also disclosed are numerous variations and refinements concerning the estimation of remaining channel capacity, the distribution of such capacity among the various producers, and the use of its allocation grant by each producer.

Abstract: Techniques to adjust the phase rotation of a modulated signal to compensate for the phase rotation introduced by circuit elements associated with the transmit signal path. In one implementation, at least one control signal is received, with each control signal being provided to adjust a particular characteristic (e.g., gain, bias current) of one or more circuit elements (e.g., VGA, PA) associated with the transmit signal path. The circuit elements can be located directly in, or operatively coupled to, the transmit signal path. A phase rotation corresponding to an operating state defined by the received control signal(s) is then determined, and the phase of the modulated signal is rotated by an amount related to the determined phase rotation. The phase rotation compensation can be performed at various locations along the transmit signal path by rotating either the data, the PN sequences used to spectrally spread the data, or the carrier signals used to modulate the data.

Abstract: Method and apparatus that compensates for overestimation of channel SINR due to overfitting of an adaptive equalizer to the pilot portion of a received frame. The SINR of a wireless channel is estimated by adapting an adaptive equalizer using the pilot portion of the frame, applying the adaptive equalizer to a non-pilot portion of the frame, determining a parameter using the adaptive equalizer output, and estimating the SINR of the wireless channel using the parameter. The parameter can include, for example, the mean square error (MSE) or the bias of the equalizer output. The accuracy of the SINR estimate according to this aspect of the present invention is thereby improved (as compared to a SINR estimate based on parameters calculated during the pilot interval) because the adaptive equalizer is not overfit to the control or data portions of the frame.

Abstract: This disclosure is directed toward a wireless device configured to support a plurality of wireless protocols. More specifically, the wireless device includes signal processing components that can be used in more than one communication mode. Accordingly, distinct components conventionally used in a wireless device that supports a plurality of protocols may be eliminated in favor of one or more common components that can be used in the different communication modes. In one example, an analog filter is used to filter baseband signals associated with a first protocol and a second protocol. A digital filter can then be used to perform additional filtering on digital baseband signals associated with the second protocol. By using a common analog filter for analog filtering of baseband signals associated with different protocols, the architecture and design of a wireless device can be simplified.