Abstract: A system and method for suppressing spurious signal leakage in a mobile terminal antenna interface without degrading switch linearity or system insertion loss is disclosed. The antenna interface includes an antenna port, a receive port, a transmit port, and a plurality of switch modes, that may include a receive mode, a transmit mode, and a special isolation mode. To suppress spurious signal leakage from high band transmit and receive ports, a switching mechanism is employed to isolate the receive port from the antenna port in high band transmit mode, and to isolate the transmit port from the antenna port in high band receive mode. A special isolation mode allows simultaneous isolation of the high band transmit and receive ports from the antenna port in low band transmit and receive modes. DC current control circuitry is optionally employed to reduce current drain in transmit and special isolation modes, extending battery life.

Abstract: A parallel cascaded set of transceivers using phase locked loops comprises a PCM communication link therebetween. At a first transceiver station, a primary framer receives an incoming signal. The primary framer extracts a payload signal and a clock signal and splits both. One clock signal is directed to the phase locked loop and the other clock signal is directed to a downstream transceiver. In this manner, start up delay and error introduction are reduced.

Abstract: A receiver for a multi-carrier CDMA system receives a signal transmitted having a known pilot sequence on plural sub-carriers. The system includes plural down-converters for down-converting the received signal to baseband signals. A delay and channel estimator correlates at least one of the baseband signals with a single wideband pilot signal, the single wideband pilot signal including all of the known pilot sequences, to produce an estimate of channel gain and multi-path delay. Plural demodulators, one for each of the plural sub carriers, are operatively coupled to the delay and channel estimator, each for demodulating one of the plural baseband signals using the estimate of channel gain and multi-path delay.

Abstract: Data is wirelessly transmitted from a base station, and/or wirelessly received at a plurality of subscriber stations that are at a plurality of distances from the base station using a Time Division Multiple Access (TDMA) frame by transmitting a same amount of data to each of the subscriber stations at a same power level during the TDMA frame while varying at least one other parameter as a function of the distance of the respective subscriber station from the base station. The at least one other parameter may be an amount of error correction coding, a sub-period duration in the TDMA frame, a number of modulation symbols from a set of modulation symbols and/or a number of sub-periods of the TDMA frame.

Abstract: A mobile radiotelephone terminal having a satellite radiotelephone and a Global Positioning System (GPS) obtains a coarse position of the mobile radiotelephone terminal from satellite radiotelephone system communications. The GPS receiver uses the coarse position to determine an accurate position of the mobile radiotelephone terminal. Accordingly, by obtaining a coarse position from the satellite radiotelephone systems communications, the computation time for the GPS receiver to compute an accurate position of the mobile radiotelephone terminal may be reduced. By allowing a reduction of computation time by the GPS receiver, an accurate position may be obtained more quickly and/or with reduced power.

Abstract: Method and apparatus for accessing a network using remote subscriber identity information. Subscriber identity information in a memory store within a device such as a mobile terminal can be remotely used by a second independent device. In the case of a GSM terminal, for example, one terminal would be able to utilize the subscriber identity information contained in the subscriber identity module (SIM) of another terminal by establishing a local communication link between the two terminals. Remote subscriber identity information is transferred over the local communication link and the communication terminal, which is using the remote subscriber identity information can register with the network using that information, thus, eliminating the need to transfer the SIM.

Abstract: A method and system reduce multipath signal interference in a CDMA receiver. The CDMA receiver including parallel first and second RAKE receivers receives a multipath signal. The first RAKE receiver includes a number of individual RAKE fingers, each operating with a defined finger delay matched to a propagation path delay. The output signal from each RAKE finger includes multipath interference. The second RAKE receiver includes a group of RAKE fingers corresponding to each RAKE finger in the first RAKE receiver. Each group of RAKE fingers is configured to produce an estimate of the multipath interference in the output signal generated by the corresponding RAKE finger in the first RAKE receiver. The estimated multipath interference signals are scaled, and then subtracted from the RAKE finger outputs from the first RAKE receiver to reduce multipath interference. Scaling coefficients are adjusted to ensure that such subtraction effectively reduces multipath interference.

Abstract: An Automatic Frequency Control (AFC) circuit for a mobile terminal employs a fractional-N Phase Locked Loop (PLL) to directly reduce errors in the synthesized frequency, such as due to component tolerances, temperature drift, and the like. The frequency error is detected by the average speed of rotation of the I,Q constellation. A corresponding offset is added to the tuning frequency selection word prior to encoding, such as in a ?? modulator, to generate an effective non-integer PLL frequency division factor over a specified duration. The ?? modulator may include dithering the different integer values by a pseudo-random number to minimize noise in the output frequency spectrum introduced by the fractional-N division. Component and parameter selection allow a high degree of resolution in frequency control of the fractional-N PLL. By directly controlling for the frequency error, a DAC and XTAL oscillator tuning circuit may be eliminated from the AFC circuit.

Abstract: A mobile radiocommunications terminal contains or is operatively connected to a position estimator, such as a GPS receiver. The mobile terminal stores at least one reference position. The mobile terminal updates its position at a frequency that is a function of its distance from the reference position, or as a function of the rate of change of its distance from the reference position.

Abstract: Signal parameter information can be transmitted from a first communications device to a second communications device. For example, communications can be received at the first communications device from the second communications device, and a plurality of samples of a signal parameter can be generated characterizing the received communications. In addition, a plurality of delta-modulation values can be calculated responsive to the respective samples of the signal parameter wherein the plurality of delta-modulation values are associated with corresponding ones of the plurality of samples of the signal parameter characterizing the received communications. The delta-modulation values can be transmitted to the second communications device. Related devices are also discussed.

Abstract: Methods and apparatus for echo and noise cancelation contemplate occasional saturation of an echo and/or noise containing source signal and control adaptation of a cancelation filter to minimize the detrimental effects of such source signal saturation. According to exemplary embodiments, filter coefficients of an adaptive filter are updated only when a prevailing value of the source signal is within a predetermined range of possible source signal values. Consequently, the filter response is not perturbed by source signal saturation, and the adaptive filter continues to provide quality echo suppression even immediately following periods of saturation.

Abstract: A system for selecting an antenna from a diversity of antennas in a DECT, PWT, or TDMA-based telecommunication system. The system combines multiple criteria to improve antenna diversity selections. The principal selection process is based on preamble diversity comparisons that operate in real-time. A preamble diversity switching circuit measures receive signal strength indicators (RSSI) from a plurality of antennas and selects the antenna that provides the highest RSSI value when the difference between the RSSI values exceeds a threshold. When the value of the RSSI difference falls below the threshold, the next selection process, a cyclical redundancy check (CRC) process is employed. The CRC process decodes a CRC value from a signal's content and compares it to a second threshold. If a CRC error is detected and the CRC value exceeds the second threshold, another antenna is selected.

Abstract: Methods, systems and computer program products are provided for accessing an embedded web server of a broadband access terminal by monitoring communications on at least one of a wide area network connection and a local area network connection of the broadband access terminal so as to determine a domain name server and/or a network gateway associated with the wide area network and accessed by a user terminal using the broadband access terminal. When the wide area network connection of the broadband access terminal is detected as unavailable, the broadband access terminal responds to communications from the user terminal to the domain server and/or the network gateway as if the domain name server and/or network gateway are accessible over the wide area network.

Abstract: A joint demodulator is configured to generate an estimated first frequency or first frequency error for the first signal and an estimated second frequency or second frequency error for the second signal. A first long-term automatic frequency control is responsive to the estimated first frequency or first frequency error, wherein the joint demodulator is responsive to the first long-term automatic frequency control. A second long-term automatic frequency control is responsive to the estimated second frequency or second frequency error, wherein the joint demodulator is responsive to the second long-term automatic frequency control. First and second local automatic frequency controls also may be included in the joint demodulator, wherein the first long-term automatic frequency control is responsive to the first local automatic frequency control and the second long-term automatic frequency control is responsive to the second local automatic frequency control.

Abstract: Systems and methods for despreading received spread spectrum signals are described. Despreading can be performed using both channel estimates and impairment correlation estimates. Techniques for selecting delays of interest are also described, along with a despreading mechanism which saves power by operating only on delays of interest.

Abstract: A telecommunications system and method is disclosed for load sharing within a CDMA2000 network. The queue size of a sector (or cell) is compared with a predefined threshold. If the queue size exceeds the predefined threshold, one or more mobile terminals having their Data Rate Control (DRC) pointed towards that sector are selected to discontinue using that sector. The network transmits a message to the selected mobile terminals informing the selected mobile terminals that their DRC is no longer valid. In response, the selected mobile terminals stop pointing their DRC towards that sector, which results in an interruption of the selected mobile terminal's data sessions. To continue their data sessions, each of the selected mobile terminals may initiate a “virtual” handoff to another sector.

Abstract: A radio frequency power amplifier circuit provides linear amplitude modulation of a radio frequency output signal while operating in a saturated amplification mode. The power amplifier circuit incorporates a lossy modulator that functions as a variable resistance responsive to an amplitude modulation signal. A supply voltage is coupled to the voltage supply input of the power amplifier circuit through the lossy modulator, such that the supply voltage applied to the power amplifier varies with the amplitude modulation signal. The radio frequency power amplifier circuit modulates the envelope of an RF output signal generated by saturated mode amplification of a constant envelope radio frequency input signal.

Abstract: Multipath delay estimation of a direct sequence spread spectrum (DS-SS) signal transmitted in a multipath fading channel is accomplished by measuring the envelope of the signal to determine a new delay estimate. Delay estimates are also obtained in ray strength order, by subtracting out the influence of the stronger rays on the weaker ones. This subtraction approach can be performed iteratively, allowing further refinement of the delay estimates. Delay estimates can also be determined by minimizing the mean square error (MSE) between a measured correlation function and a modeled correlation function. The minimum mean square error (MMSE) approach can performed iteratively, to further refine the delay estimates. Maximum likelihood (ML) delay estimates can also be obtained by exploiting side information regarding the transmit and receive pulse shapes.

Abstract: An adaptive radio receiver utilizes control functions derived from received signals in an interference-limited environment to decide whether to implement conventional single-user demodulation or joint demodulation. The decision to implement joint or conventional demodulation is based upon the values of estimates derived for Doppler spread, carrier-to-interference plus noise, dispersiveness and the likelihood of the presence of a dominant interferer.

Abstract: Methods and systems for selectively encrypting and decrypting messages transmitted on a channel of a communication network, such as a broadcast channel, are provided. Group encryption keys are provided for one or more services utilizing the broadcast channel to communicate messages. A message associated with a particular service first receives an error check value, such as a cyclical redundancy check (CRC) value generated from the unencrypted message. The message is then encrypted using the group encryption key for the service and the CRC is added to the encrypted message and transmitted with a broadcast address of the communication network. A receiver then receives the message and determines that the CRC indicates an error (as it is generated from the encrypted message rather than the unencrypted message). The receiver then decrypts the message using the group encryption key for the service (assuming the receiver is authorized to receive the service, i.e.