Abstract: A system and method for determining the geolocation of a transmitter within or without a set of receiving stations. The system includes plural receiving stations which determine the time of arrival and the angle of arrival of a signal from a target unit. The signal determinations are communicated to a central processing unit which determines the geolocation of a radiating unit which would provide such times of arrival and angles of arrival. By use of both time of arrival and angle of arrival information at the central processing unit, the need for receiving stations to cover a desired geographic area is reduced.

Abstract: A digital rate change filter with multiple stages and including sampling rate compression and following offsetting expansion about a lowpass filter. Phantom decimation and interpolation rates are used as approximates to actual rates, the phantom rates allow near optimal factoring into rates for two-stage filters, and linkage of these factors to actual rates are efficiently made.

Abstract: A telephone system coder/decoder (CODEC) having improved access for testing CODEC components and a method of testing a CODEC in which a test signal is not contaminated by passage through CODEC filters. Input test pads are positioned between the receive channel filters and the connection of the receive channel to the hybrid balance network, and an output test pad is positioned between the transmit channel filters and the connection of the transmit channel to the hybrid balance network. Test signals selectively applied to the test pads or to CODEC terminals indicate operation of receive programmable gain section, hybrid balance network frequency response, hybrid balance network echo cancellation, and the transmit buffer, buffer splitter and transmit programmable gain section in the transmit channel. The test signals do not go through the transmit and receive filters.

Abstract: The faulted sections are evaluated by calculating the measuring information resulted from the faults in various positions by the previous fault simulative calculation, introducing the resulting fault simulative measuring information into a self-organizing neural network having output elements of which number being more than that of input elements to permit the self-organizing neural network to learn the classification of the simulative measuring information, preparing an evaluation rule representing the correspondent relation between the output from the classification of the stimulative measuring information and the faulted position, thereafter introducing actual measured information into the self-organizing neural network to permit the self-organizing neural network to classify the introduced actual measured information, and evaluating the faulted section from an output classified by the self-organized neural network on the basis of the evaluation rule.

Abstract: A method and apparatus for receiving and transmitting direct sequence spread spectrum signals uses a single integrated device for converting and demodulating an RF signal into a serial data signal. Critical timing relationships during the acquisition and demodulation of the received signal are satisfied by the use of an integrated circuit specially designed to perform all operations needed to convert the physical signal to an media access circuit level data signal.

Abstract: A method and system for adjusting the gain of an output from a replacement component in a system with plural components responsive to changing operating conditions so that a power level of an output from the system is approximately the same as a power level of an output from the system before installation of the replacement component. A system memory stores a relationship of gain responsive to changing operating conditions for each of plural components in the system, and each replacement component has a component memory for storing a relationship of gain responsive to changing operating conditions. The relationship stored in the component memory is copied to the system memory when the replacement component is installed in the system.

Abstract: A direct sequence spread spectrum receiver and method for acquiring radio-frequency signals is provided for acquiring data from signals which have been transmitted in a spread spectrum system. The receiver is capable of receiving short data bursts from transmitters without prior knowledge of the time or location of the transmission and rapidly acquiring the signal before continuing with reliable data demodulation. The system includes one or more antennae for receiving RF signals which may be selectively connected to provide the received signals to the system for processing, a quadrature demodulator for providing I and Q baseband signals to a digital baseband processor which includes A/D converters, dual correlators for despreading the digital I and Q signals, a cartesian to polar converter, a demodulator for demodulating the polar coordinate digital I and Q signals, and a data descrambler for obtaining a serial data stream which may be provided to a serial interface.

Abstract: A system and method for compressing speech using an artificial neural network to calculate the recoded phase vector (Mozer code) resulting from the spectral magnitude-to-phase transformation. Raw speech is equalized to remove the spectral tilt and segmented into analysis frames. The spectral magnitudes of each frame segment are determined at a plurality of points by a Fourier Transform, normalized, and applied to a neural net magnitude-to-phase transform calculator to provide a recoded phase vector. An Inverse Discrete Fourier Transform is used to calculate the new recoded speech waveform in which the two quarters with minimum power are zeroed to produce the compressed speech output signal.

Abstract: A filter element is constructed such that a filter material having a corrugated sectional surface is formed in the shape of a cylindrical housing, and an upper opening portion of the cylindrical housing is kept closed, and an lower opening portion is connected to an air suction duct. A row of hills and valleys of the corrugated sectional surface is formed with a certain front angle relative to the wall surface of the cylindrical casing.

Abstract: A system and method for processing video imagery. The system automatically selects for transmission, or storage, portions of a video image at an automatically selected compression level, and/or in an automatically selected order. The system and method are intended to supplement and/or replace human actions with autonomous operations that are intended to preserve and prioritize important image information and highly reduce or eliminate image data that does not contain significant information. The preservation of important and relevant image information is given a higher priority than preservation of overall image quality.

Abstract: A current generator and method of making a current generator in which two resistors are provided, each in series with one of two transistors in the generator, and in which one of the resistors is trimmed if the reference current is too large and the other is trimmed if the reference current is too small, thereby obviating the problems of the prior art in which one resistor must be trimmed by a potentially large and unacceptable amount. The two resistors are formed with a distribution of resistances which is centered on their corresponding target resistance values so that the number of resistors to be trimmed and the amount of trimming per resistor are reduced. The appropriate target resistances of the resistors can be determined if a maximum trim factor is set. The method is insensitive to variations in the process by which the resistances of the resistors are initially set and reduces the variability of the untrimmed reference current with respect to resistor critical dimensions.

Abstract: A system and method for tracking a remote RF transmitter with reduced susceptibility to the effects of multipath in which the distance and direction of an arriving RF chirp signal are determined with respect to the earliest arriving portion of the signal which is presumed to be the direct path signal. The received chirp signals, including the direct and multipath signals, from a remote transmitter are correlated into plural path signals, and the direction and distance to the transmitter is determined from the earliest arriving path signal.

Abstract: A method of attenuating vibrations, and a vibration attenuating actuator for attachment to a vibration transmitting structural member include an annular proof mass for attenuating vibrations. The proof mass is concentrically mounted without bearings on the strut so as to attenuate vibrations being transmitted therethrough without imparting a moment to the strut, and without affecting the structural integrity of the strut. The annular proof mass is moved parallel to the strut's longitudinal axis so that the actuator imparts a vibration attenuating force coaxial with the strut's longitudinal axis. The actuator may be used with feedforward and feedback controllers.

Abstract: A differential, interpolating, switched capacitor filter and method of operation in which non-interpolating stages of the filter are clocked at a first frequency and a subsequent interpolating stage of the filter is operated at double the first frequency to achieve improved smoothing of the output wave form. The switched capacitors in the interpolating stage which feed forward a differential input from a prior stage to an input to the interpolating stage, and which feed a differential output from the interpolating stage back to an input thereto are paired and switches are provided for the added capacitors so that all of these capacitors are switched. Capacitors which are directly coupled to feed forward a differential input from a prior stage to the interpolating stage are also paired, but only the added capacitor is switched.

Abstract: A system and method for identifying and controlling an unknown dynamic system in which the system is identified, at least in part from test data, and a control scheme may be adapted on-line. In addition, the system may be used to develop an off-line solution to complex problems related to both dynamic and static systems. The system may use a multiprocessor architecture which may have a variety of configurations but is particularly suited for a neural network. The neural network may be built up of neurons that are either purely one way (forward signal path) or two way. Each neuron may be provided with its own synaptic weight, adjusted using only the local and backward signals.

Abstract: An emulator circuit and method of emulating operation of a computer system in which the emulator circuit may be selectively operated with memory devices that require coincident availability of data and address information during a clock cycle, and with systems that require data and address information at different times during the clock cycle. (Address information including address signals for selecting memory locations and memory control signals.

Abstract: A method and circuit for controlling a reference voltage for an analog-to-digital converter having plural outputs includes a sensor for indicating when outputs from the A/D converter are at least a desired voltage, and a processor responsive to the sensor and connected to a digital-to-analog converter which provides a reference voltage for the A/D converter. The processor provides signals to the D/A converter which change the reference voltage. A logic unit in the processor increments an accumulator when either an I or a Q component in the A/D converter output is at least the desired voltage and decrements the accumulator when neither the I nor the Q component is at least the desired voltage. A counter may buffer the accumulator changes by using only several of the most significant bits of the counter to change the A/D converter reference voltage.

Abstract: A method and circuit for preventing forward bias of a collector-substrate diode in an integrated circuit with a bipolar transistor where a load driven by the transistor may be offset from a reference voltage, such as circuit ground, by a varying voltage offset. The difference between the bipolar transistor collector voltage and the reference voltage is sensed, and the bipolar transistor base current is varied responsive to the sensed difference so that the base current is zero when the collector voltage is equal to the reference voltage, whereby the collector current will be less than .beta. times the base current when the emitter voltage is less than the reference voltage and the diode will not become forward biased.

Abstract: A thread forming screw for concrete, masonry, rock, or similar material. The size ratios of various portions of the screw are defined to reduce thread engagement which, in turn, reduces screw-in torque. A burr in the screw's thread includes bow-shaped cutting teeth to facilitate screw-in.

Abstract: A Class D (audio) amplifier and method in which an input signal for the amplifier is pulse width modulated outside of the amplifier's feedback loop, and in which the pulse width modulated input signal and a pulsed signal from the feedback loop are summed in the feedback loop and fed back to the amplifier. The removal of the pulse width modulation stage and signal integration stage from the feedback loop improves distortion.