Abstract: A DC offset correction method and apparatus. In a DC offset correction loop (100), a DC offset is corrected using a binary search routine or any other digital or analog DC offset correction technique. In this binary search routine, the sign of the offset (138) is used to control a direction in which a digital to analog converter (DAC) (166) is stepped until the least significant bit of the DAC is set. The process is enhanced by opening up the bandwidth of the baseband filters (130) to permit the binary search to be clocked (180) at a higher clock rate. After the correction is established, the filters (130) are reset to normal operating conditions.

Abstract: A load envelope following (LEF) amplifier system to increase the efficiency of amplification systems that employ linear modulation schemes. The LEF system has a signal amplifier for receiving an input signal that has an amplitude modulation (AM) envelope. The signal amplifier produces an amplified version of the input signal. A variable impedance network is coupled to an output of the signal amplifier and substantially continuously presents various impedances to the output of the signal amplifier in response to a load control signal. An envelope mapping circuit is coupled to the variable impedance network to produce the load control signal in response to and indicative of the substantially continuously varying amplitude of the AM envelope of the input signal.

Abstract: An adaptive garbage collection scheduler (42) in an interactive system (10) to schedule invocation of a mark and sweep garbage collection process. The adaptive garbage collection scheduler (42) determines a user impact index (I), corresponding to the effect of the garbage collection process on a user (22), and a collection urgency index (U), corresponding to how urgently the garbage collection process needs to be run. The garbage collection process is invoked by the adaptive garbage collection scheduler (42) when the collection urgency index (U) is greater than the user impact index (I).

Abstract: A DC offset correction loop (200, 300) utilizes a peak estimator (218, 322) to determine peaks associated with a digital signal (238, 338). The peak estimator (218, 322) averages the peaks in order to estimate the DC offset. A summer (216, 326) sums the DC offset (242, 350) with the digital signal to produce a corrected output.

Abstract: A communication device for simultaneously transmitting information on multiple sub-channels encodes information for each of the multiple sub-channels with a coding scheme to produce channel encoded information. A mask vector derived from a redundancy in the coding scheme, encodes the channel encoded information to transform the channel encoded information into codewords having pairwise Euclidean distance properties identical to those of the channel encoded information, Modulation of the sub-channels in accordance with the codewords in a modulator then produces a composite signal envelope having a peak-to-mean error power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated channel encoded information.

Abstract: A multiple frequency band receiver (102) receives at least two frequency bands that are close but not adjacent. A first bandpass filter (304) passes signals in the first frequency band. A second bandpass filter (306) passes signals in the second frequency band. The first and second filters each attenuate signals between the first and second frequency band to at least a first level so as to provide selectivity in the frequency range between the first and second frequencies to prevent the signals between these frequency bands from being further processed by the communication device. A third filter (322) coupled to first and second filters passes signals in both the first and second frequency band and attenuates signals above the pass band of the higher of the first and second filters and below the lower of the first and second filters.

Abstract: A window error detector for a receiver capable of operating in a discontinuous transmit mode includes a soft decision decoder (210) producing soft output and generating window error signals. A detector (214) is coupled to the soft decision decoder for detecting a bad frame when the window error exceeds a bad frame threshold, wherein the threshold is altered based on the discontinuous transmit state. A turbo decoder (210) for a receiver includes a soft decision decoder and a window error detector (214) coupled to the soft decision decoder. The window error detector generates a bad frame indication. The turbo decoder stops iterative processing of the data associated with a window when the window error detector detects that the window does not result in a bad frame indication.

Abstract: A voice recognition system (204, 206, 207, 208) generates a variable rejection strictness as a function of at least one background noise level measured during training and noise signal measurements made during an input utterance made during recognition mode of operation. A word entrance penalty is assigned as a function of the variable rejection strictness.

Abstract: An amplifier circuit (100) includes a power amplifier (124) that has a modulated power supply input (125). The modulated power supply input (125) is modulated with a signal related to the amplitude of the signal being amplified by the power amplifier (124). The power amplifier (124) is maintained at a substantially constant operating point. The amplifier circuit (100) also includes a feedback path that generates an error signal as a function of the input signal envelope and the output signal envelope. The error signal is integrated and the resulting integrated error signal drives the gain control of a variable gain element (120) in the amplifier chain prior to the power amplifier (124).

Abstract: A voice recognition system (204, 206, 207, 208) assigns a penalty to a score in a voice recognition system. The system generates a lower threshold for the number of frames assigned to at least one state of at least one model and an upper threshold for the number of frames assigned to at least one state of at least one model. The system assigns an out of state transition penalty to an out of state transition score in an allocation assignment algorithm if the lower threshold has not been met. The out of state transition penalty is proportional to the number of frames that the dwell time is below the lower threshold. A self loop penalty is applied to a self loop score if the upper threshold number of frames assigned to a state has been exceeded. The out of state transition penalty is proportional to the number of frames that the dwell time is above the upper threshold.

Abstract: A smoke detector includes a housing defining a dark chamber admitting test atmosphere. A light receiver is disposed within the chamber. A scatter emitter is positioned within the chamber such that light strikes the receiver when reflected off particles suspended in the test atmosphere. An obscuration emitter is positioned within the chamber such that light emitted is directed to the receiver unless obstructed by particles suspended in the test atmosphere. A smoke detect signal is generated responsive to a measurement made responsive to the scatter emitter and/or the obscuration emitter.

Abstract: A decoder circuit includes a probability circuit which generates branch metrics using bit-wise probabilities representing frame-to-frame correlation relationships. The branch metrics are input to a decoder which outputs decoded data bits as a function of the bit-wise probabilities for at least predetermined bit positions.

Abstract: A method of extracting features for a voice recognition system of a wireless communication device. The wireless communication device includes a transmitter and a receiver coupled to a call processor, a microphone for inputting audible sounds, and an analog-to-digital converter coupled to the microphone to output digital signals. The call processor includes a coefficient generator coupled to the analog-to-digital converter and generating representative coefficients, a differentiator coupled to the coefficient generator to generate delta coefficients, and an extractor outputting a portion of the representative coefficients and the delta coefficients as a feature vector for use in voice recognition, wherein every other representative coefficient is used in the feature vector.

Abstract: A radiotelephone system (100) includes a radiotelephone (102) and a central device (104) that communicate via radio frequency (RF) signals. The radiotelephone (102) includes a user interface (114) which permits the user to request a channel change by the central device. A signal is communicated to the user if a channel change is denied. A channel scan can be conducted by the radiotelephone to identify a new channel.

Abstract: A display circuit, and associated method, including a high-persistence display element, such as a liquid crystal display device, which visually displays sequences of informational image frames while minimizing interference between successive ones of the frames. A sequence of informational image frames are displayed upon the display element, thereby to generate a visual signal which appears to scroll across the display element. Blank image frames are interspersed between successive ones of the informational image frames to reduce thereby interference between successive ones of the informational image frames.

Abstract: A card (922) comprises a body (909). A connector (522) is carried on the body for coupling to a communication device (900). A user interface including a keypad (926) is carried on the body and coupled to the connector. An identity circuit (904) is coupled to the connector. The identity circuit can be a GSM SIM. The card can include an aperture (924) for alignment with a display on a device with which the card is used.

Abstract: A direct modulation phase lock loop (PLL) a voltage controlled oscillator (VCO) (114). A divider (118) has a first divider input coupled to the VCO and a second divider input to receive a modulation inducing divisor sequence. A phase detector (102) has a first detector input coupled to the divider to receive the output thereof, and a second detector input to receive a reference input. A tuning circuit (306, 406) is coupled to the phase detector and the VCO, the tuning circuit responsive to a variable DC reference potential such that the tuning circuit has a frequency response that is constant over the modulation bandwidth whereby the PLL is a type 1 PLL with low modulation distortion.

Abstract: A mid supply reference generator (100, 200, 300) has a first resistance element (106, 206) coupled to a first supply. A second resistance element (108, 208) is coupled to a second supply. A third resistance element (110, 210) is coupled to the second supply A first transistor element (116, 216) is coupled to the first resistance element and the second resistance element, the first transistor element coupled between the first and second resistance element such that the first and second resistance elements provide a reference voltage drop from the same current level. A second transistor element is (120, 220) coupled between the first supply and the mid supply output, the second transistor element to drive the output providing a desired mid supply potential. A third transistor element (118,218) is coupled to the mid supply output and to the third resistance element, the third transistor element and the first transistor element being connected such that they generate proportional currents.

Abstract: A vibrator bracket 224 for mounting a vibrator 226 including a motor 228, a shaft 231 controlled by the motor and weight 232. The bracket has members (260, 261) to engage the motor. The bracket has a shaft support, including an opening 275 for receipt of an end of the shaft remote form the motor whereby the shaft is positioned in the opening and deflection of the shaft is limited by the support.

Abstract: A multiple band mixer (204) includes at least one transistor element (313, 324, 400). A single local oscillator provides a signal to one terminal of the at least one transistor element. The communication signals for each frequency band is input to the at least one transistor element at another terminal. A third terminal of the at least one transistor element is connected to the output.