Using A Particular Modulation (e.g., Phase, Frequency, Or Amplitude) Patents (Class 340/870.18)
  • Patent number: 7529300
    Abstract: Shaped Offset Quadrature Amplitude Modulation (QAM) can be implemented within a communication system. A train or sequence of orthogonal sinc pulses can be generated for each of the in-phase and quadrature signal paths. The sinc pulses in the quadrature signal path can have a predetermined time offset relative to the pulses in the in-phase signal path. An in-phase or quadrature antipodal data signal can be used to modulate the respective sinc pulse train. Each of the in-phase and quadrature pulses can be shaped using a time domain windowing function, such as a Kaiser-Bessel window, to adjust the spectral width and spectral sidelobe level of the signal. The beta parameter of the window can be adjusted to achieve the desired signal response. The timing of the sinc pulses may need to be adjusted following the window function in order to maintain orthogonality of the pulses.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: May 5, 2009
    Assignee: Cubic Corporation
    Inventor: Wayne Edward Richards
  • Publication number: 20090000387
    Abstract: A solution for monitoring a property of an object and/or an area using a Micro-ElectroMechanical Systems (MEMS)-based monitoring device is provided. In an embodiment of the invention, the MEMS-based monitoring device includes a MEMS-based sensing device for obtaining data based on a property of the object and/or area and a power generation device that generates power from an ambient condition of the monitoring device. In this manner, the monitoring device can operate independent of any outside power sources or other devices. Further, the monitoring device can include a transmitter that transmits a signal based on the property. The monitoring device can be used to monitor a moving component of a machine, and can be integrated with a health monitoring system of the machine using one or more relay devices.
    Type: Application
    Filed: July 11, 2008
    Publication date: January 1, 2009
    Inventors: Zahid F. Mian, Ryk E. Spoor
  • Publication number: 20080211688
    Abstract: A method and apparatus for a multi-mode and multi-rate telemetry transmitter includes a digital baseband lineup, a digital-to-analog converter (“DAC”), and an analog reconstruction filter. The digital baseband lineup may be programmed to any desired bit rate, enabling the transmitter to support multi-rate capabilities. Different coefficients and numerical values may be programmed in the digital baseband lineup to support any desired modulation scheme, enabling the transmitter to support multi-mode capabilities. The digital baseband lineup may be designed by implementing up-sampling stages, down-sampling stages, and digital filters in a variety of arrangements.
    Type: Application
    Filed: September 24, 2007
    Publication date: September 4, 2008
    Inventor: Walid Khairy Mohamed Ahmed
  • Patent number: 7412899
    Abstract: A solution for monitoring a property of an object and/or an area using a Micro-ElectroMechanical Systems (MEMS)-based monitoring device is provided. In an embodiment of the invention, the MEMS-based monitoring device includes a MEMS-based sensing device for obtaining data based on a property of the object and/or area and a power generation device that generates power from an ambient condition of the monitoring device. In this manner, the monitoring device can operate independent of any outside power sources or other devices. Further, the monitoring device can include a transmitter that transmits a signal based on the property. The monitoring device can be used to monitor a moving component of a machine, and can be integrated with a health monitoring system of the machine using one or more relay devices.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: August 19, 2008
    Assignee: International Electronic Machines Corporation
    Inventors: Zahid F. Mian, Ryk E. Spoor
  • Publication number: 20080180278
    Abstract: This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device. The amplifier may be used for physiological signal sensing, impedance sensing, telemetry or other test and measurement applications.
    Type: Application
    Filed: January 31, 2007
    Publication date: July 31, 2008
    Applicant: Medtronic, Inc.
    Inventor: Timothy J. Denison
  • Patent number: 7382208
    Abstract: The operating method is based on the simultaneous application of FM and AM. In this process, the fundamental frequency of the AM is derived from at least one, preferably the second, longitudinal mode. In continuous operation of the lamp, the color temperature is set for a prescribed power by setting the AM degree controllably.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: June 3, 2008
    Assignee: Patent-Treuhand-Gesellschaft für Elektrische Glühlampen MbH
    Inventor: Klaus Stockwald
  • Patent number: 7324011
    Abstract: A pipeline communication system and method includes a pipeline having a surface extending along at least a portion of the length of the pipeline. A conductive bus is formed to and extends along a portion of the surface of the pipeline. The conductive bus includes a first conductive trace and a second conductive trace with the first and second conductive traces being adapted to conformally couple with a pipeline at the surface extending along at least a portion of the length of the pipeline. A transmitter for sending information along the conductive bus on the pipeline is coupled thereto and a receiver for receiving the information from the conductive bus on the pipeline is also couple to the conductive bus.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: January 29, 2008
    Assignee: Battelle Energy Alliance, LLC
    Inventor: John G. Richardson
  • Patent number: 7265682
    Abstract: Methods and systems employing combined source-channel coding for multi-carrier modulation (MCM). In some embodiments, a described method comprises: estimating channel gain to noise ratio (CGNR) as a function of frequency bin; determining MCM parameters that minimize distortion of one or more telemetry signals; generating a communications signal using the MCM parameters, and transmitting the communications signal via a communications channel. The MCM parameters may be determined by minimizing a telemetry signal distortion measure subject to CGNR and a transmit power constraint. The MCM parameters may further account for differing fidelity requirements when multiple telemetry signals are being transmitted.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: September 4, 2007
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Mahsa Memarzadeh, Wallace R. Gardner, Don Herrick Johnson
  • Patent number: 7193511
    Abstract: A rapid-mounting security monitoring and controlling system is disclosed. Co-axial cable is used to transmit power supply, images, sound, and to control detected signals so as to rapidly installation of wirings for the security monitoring and controlling system. The complexity of wiring installation is improved and the installation cost and the material cost are greatly reduced.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: March 20, 2007
    Assignee: AV Tech Corporation
    Inventor: Chun-Ju Huang
  • Patent number: 7133763
    Abstract: The invention provides a control apparatus comprising a controller for determining a manipulated variable for manipulating a controlled object so that an output of the controlled object converges to a desired value and a modulator for modulating the manipulated variable by using one of a delta-sigma modulation algorithm, a sigma-delta modulation algorithm and a delta modulation algorithm to generate a modulated signal to be applied to the controlled object. The modulator generates the modulated signal so that a center value of an amplitude of the modulated signal follows a change of the manipulated variable. Thus, the modulated signal in which the manipulated variable is reflected without any loss can be generated even when the manipulated variable changes.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: November 7, 2006
    Assignee: Honda Motor Co., Ltd.
    Inventor: Yuji Yasui
  • Patent number: 7102534
    Abstract: An apparatus measures temperature of a reciprocating piston and comprises one or more thermocouples of which one end is inserted to a predetermined point of the piston and generates a potential difference according to temperature of the predetermined point. A telemetry unit is mounted on a big end of a connecting rod, computes the piston temperature on the basis of the potential difference, and wirelessly transmits the piston temperature signal.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: September 5, 2006
    Assignee: Hyundai Motor Company
    Inventor: Kyoung-Pyo Ha
  • Patent number: 7102509
    Abstract: A method for operating with multiple protocols for handling communications comprising the steps of obtaining information from sensors and related input devices utilizing specialized tamper resistant passive transceivers working with active pulse type transceivers to create historical maps of information on people or objects. This includes steps of: a) identifying recording information, b) sending and receiving prompts, c) associating the call with timers, d) monitoring passive transceivers with low level diagnostic information, e) monitoring the transceivers with voice recognition software, f) recording associated data, g) identifying the users, the key words or phrases within the recorded data, h) naming the recording and i) saving the data in a protected format.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: September 5, 2006
    Assignee: Global Tel★Link Corporation
    Inventors: Joseph Anders, Jeremy Birch, Bryan Wilson, Marty Logsdon
  • Patent number: 7084741
    Abstract: A method for communicating between a first station and a second station over a wire pair, in which the first station sends an alternating power signal over the wire pair, the alternating power signal comprising a plurality of communication symbols, the second station receiving the alternating power signal and determining therefrom the communication symbols, the second station drawing current from the alternating power signal in a sequence corresponding to at least one further communication symbol, and the first station determining the current drawn in the alternating power signal to recover the further communication symbol.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: August 1, 2006
    Assignee: Signal Data Systems PTY, Ltd.
    Inventor: Allan P. Plummer
  • Patent number: 7027357
    Abstract: The present invention provides an acoustic transmitter for sequentially transmitting a plurality of pulse signals by sound. Each of the plurality of pulse signals is a signal of at least one modulated carrier wave, which has a predetermined frequency. The carrier wave of each of the pulse signals has a mutually different frequency. The transmitter performs amplitude modulation and/or phase modulation based on transmission information, and modulation by a signal indicating a window function, for the carrier wave of each of pulse signals. Then the transmitter sequentially transmits the plurality of pulse signals by sound.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: April 11, 2006
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Hirohisa Sakuma, Jun Fujiwara
  • Patent number: 7016403
    Abstract: An apparatus and method for determining the quality of a digital signal. The incoming digital signal is sampled with a number n of samples per defined pulse width, where N is greater than or equal to one, using clock cycles. An edge detector detects the edge position of a pulse of the sampled digital signal and a counter counts the clock cycles between at least a first edge and a second edge detected by the edge detector. A deviation detector then compares the counted clock cycles with a prestored reference-value in order to provide a deviation value as a measure for the instantaneous quality of the digital signal. The deviation value is then fed to a rework unit that outputs a value that is a measure for the quality of the digital signal.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: March 21, 2006
    Assignee: International Business Machines Corporation
    Inventors: Walter Hirt, Fritz Gfeller
  • Patent number: 7007305
    Abstract: A repeater amplifier boosts weak control signals on a PLC network, with noise discrimination and signal firewall protection. The AC supply voltage is filtered by a high frequency blocking filter to block external noise signals. Operating power for network signaling devices and the repeater amplifier is derived from the clean AC supply voltage. Noise discrimination and signal firewall protection are provided by amplifying and repeating only those receiver pulse signals that (a) have an analog amplitude that exceeds a predetermined analog threshold value, (b) occur during intervals that control data signal modulation is being applied to the filtered AC supply voltage and (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier (PLC) modulation frequency.
    Type: Grant
    Filed: September 6, 2001
    Date of Patent: February 28, 2006
    Assignee: Genlyte Thomas Group LLC
    Inventors: Steven R. Carson, Raymond T. Griffin
  • Patent number: 6968728
    Abstract: The present invention relates to an apparatus for measuring the capacitance and the dissipation factor in a transformer bushing and extracting gas dissolved in the insulating fluid of said bushing. The apparatus comprises a porous cylindrical member associated with a tap connector and covered by a thin layer of a gas permeable but liquid impermeable membrane. The porous member allows passive diffusion of the permeated gas extracted from the insulating fluid of a transformer bushing to a gas storage chamber for further analysis, thereby helping to prevent high costs related to damage or destruction of the bushing.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: November 29, 2005
    Assignee: Hydro Quebec
    Inventors: Roland Gilbert, Jocelyn Jalbert, Hong Phuong Nguyen, René J. Demers
  • Patent number: 6943640
    Abstract: A current source modulator (202; 302, 502) provides power to radar transmitters. The modulator comprises a power supply (210, 310, 510) providing, when enabled, a known current to a storage capacitor (145). A comparator circuit (220) provides a signal (V220) when voltage (VC) across the storage capacitor (145) falls a reference voltage, and an enable circuit (225) responds to the comparator signal (V220) and an ON command signal to enable the power supply (210, 310, 510). The modulator (202, 302, 502) further includes a network (220N) associated with the comparator circuit (220) to retain the value of the signal (provide hysteresis) when the voltage across the storage capacitor is above the reference voltage. The modulator (202, 302, 502) may include a second network (320N) associated with a second comparator circuit, operable to retain a second signal when capacitor (145) voltage VC is above a reference voltage. In this aspect, there is a rapid charge and a trickle charge that reduces any charging overshoot.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: September 13, 2005
    Assignee: Lockhead Martin Corporation
    Inventor: Gregory Alan Arlow
  • Patent number: 6871785
    Abstract: The method for compensating undesired variations in an electrical signal generated by a sensor of an optical code reader comprises the steps of generating an envelope signal starting from the electrical signal generated by the sensor and normalizing the electrical signal with respect to the envelope signal. Preferably, the envelope signal is filtered with a low-pass filter before being normalized so as to eliminate steps and edges which may cause distortions during normalization, and the normalized signal is amplified in a controlled way so as to supply an output signal ranging between two values having preset amplitudes. Normalization is carried out by dividing, point by point, the electrical signal by the envelope signal, in the case of continuous analog processing; alternatively, in presence of discrete-time signals, normalization is carried out by subtracting the envelope signal from the electrical signal.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: March 29, 2005
    Assignee: Datalogic S.p.A
    Inventors: Marco Piva, Maurizio Bianchi
  • Patent number: 6788194
    Abstract: An antenna device is composed of a plurality of units of a same structure connected in series.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: September 7, 2004
    Assignee: OMRON Corporation
    Inventor: Shuji Yamashita
  • Patent number: 6756759
    Abstract: A current target angle stored in a target angle register is subtracted from the immediately preceding target angle stored in a register by a subtracting device. As a result, the length (amount) and direction between the immediately preceding target angle to the current angle are generated. With the generated length and direction, a model acceleration generating circuit generates model acceleration data. With a count value of a current velocity detecting counter and a velocity data sequence that is output from a model velocity generating circuit, velocity error data is generated. With a count value of a current position detecting counter and a position data sequence that is output from a model position generating circuit, position error data is generated. The model acceleration data, the velocity error data, and the position error data are added by an adding device. The added result is supplied to a driver. The driver outputs a current that drives a pan motor.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: June 29, 2004
    Assignee: Sony Corporation
    Inventor: Noriyuki Yamashita
  • Publication number: 20040113814
    Abstract: In one general aspect, data transfer between the modem and a processor connected to the modem may be improved using a variable speed buffer. The variable speed buffer may include one or more first-in/first out buffers (FIFOs) and two interfaces. The FIFOs may be connected between the interfaces to form an input data path and an output data path. Each FIFO may store a complete message. Consequently, an entire message may be transferred from the processor at the processor's higher data rate without having to wait for a modulator to modulate the outgoing message at a slower data rate. The modem automatically may use characteristics of an incoming signal to detect which communications protocol is used to send a message, and perform protocol specific functions. The modem may perform system diagnostic functions to improve system performance.
    Type: Application
    Filed: December 17, 2002
    Publication date: June 17, 2004
    Inventor: Michael Lochner
  • Publication number: 20040113811
    Abstract: An mileage communication system for a vehicle, such as a trailer, is disclosed. Mileage data is communicated to a processor by a sensor. The processor calculates cumulative mileage and encodes the mileage data into a code, such as an ON-OFF code, that is capable of being communicated to an output device. The vehicle operator may activate a user interface that is capable of generating a request signal to be sent to the processor. Upon receipt of the request signal, the processor communicates the code to the output device. In response to the code from the processor, the output device communicates a visual or audible signal, such as an ON-OFF signal, that is capable of being received by the vehicle operator or other user. The signal corresponds to the cumulative mileage data.
    Type: Application
    Filed: September 8, 2003
    Publication date: June 17, 2004
    Applicant: BENDIX COMMERCIAL VEHICLE SYSTEMS LLC
    Inventor: Paul J. Waszkowski
  • Patent number: 6744367
    Abstract: An identification tag is provided comprising a multilayer assembly incorporating, in sequence, a metal backing layer, a bulk structural layer, a piezo-electric layer and an electrode layer. The electrode layer incorporates antennas structures for receiving interrogating radiation comprising a first radiation component at a relatively lower frequency and a second radiation component at a relatively higher frequency. The electrode layer also incorporates a structure for modulating a second signal generated in response to receiving the second component by a first signal generated in response to receiving the first component to generate a modulated signal which is re-emitted as reflected radiation from the tag. The presence of the tag is determinable from modulation components present in the reflected radiation, thereby distinguishing the tag from other objects capable of reflecting radiation, but not modulating it.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: June 1, 2004
    Assignee: Marconi Data Systems Limited
    Inventor: Ian Forster
  • Publication number: 20040095256
    Abstract: An integrated circuit implements a wireless remote sensor. The wireless remote sensor includes an antenna coupled to an energy distribution unit to allow passive collection of electrical charge. A signal processing unit couples to the energy distribution unit and modulates transmission by the antenna according to a binary code.
    Type: Application
    Filed: April 25, 2003
    Publication date: May 20, 2004
    Inventor: Farrokh Mohamadi
  • Publication number: 20030052790
    Abstract: A system and method for communicating information between a utility metering device, such as a water meter, and a remote location, such as inside a residence or a service provider.
    Type: Application
    Filed: September 20, 2001
    Publication date: March 20, 2003
    Inventor: Robert A. Dunstan
  • Patent number: 6529443
    Abstract: A two-conductor bidirectional digital telemetry interface between a seismic sensor acquisition/conversion module and a seismic data collection module. The data collection module is configured as a master electronics device and the sensor acquisition/conversion module is configured as a slave electronics device in the telemetry system. The master device provides power to the slave device over the two conductors. The master device transmits portions of commands to the slave device at a first time and the slave device transmits portions of a digital seismic data packet to the master at a different second time in a fixed-duration frame. The frames are transmitted at regular intervals. The outbound commands and inbound data are encoded by block codes. A phase-locked loop in the slave is locked to a master clock in the master by deriving a clock and a sync point from the block-coded commands it receives from the master.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: March 4, 2003
    Assignee: Input/Output, Inc.
    Inventors: John C. Downey, Jr., Ralph Kruse, Allen J. Bishop, Kent A. Byerly
  • Publication number: 20030020632
    Abstract: A meter interface unit for use in a one way automatic meter reading system comprises first means for frequently transmitting a short burst transmission suitable for reception by a hand held or mobile receiver, and second means for transmitting narrow band data messages suitable for reception by a fixed network first tier receiving station. The receiver at the first tier receiving station has means for suppressing the short transmissions to prevent interference with the slow busts from the second transmitting means. Repeated packet collisions between the short bursts are avoided by randomly varying the time period between the short bursts.
    Type: Application
    Filed: September 3, 2002
    Publication date: January 30, 2003
    Inventors: Terence George Giles, Kenny Steele
  • Patent number: 6492898
    Abstract: In a data transmission system for a pipeline which is electrically conductive at least in sections, the pipeline itself forms a data line. For this purpose, a coupling element is present for the modulation of electrical signals onto a potential of the pipeline. A cost-effective data transmission system is created which can be used in remote regions.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: December 10, 2002
    Assignee: ABB Research Ltd
    Inventors: Bruno Sabbattini, Josef Lehmann, Paul Rudolf, Daniel Matter
  • Publication number: 20020130802
    Abstract: A circuit assembly for a remote control is capable of learning (i.e., copying) and transmitting. The circuit assembly comprises a microprocessor, a memory, an oscillation generation circuit, a high frequency signal and frequency receiver circuit, a waveshaping circuit, a digital to analog converter (DAC), a voltage controlled oscillation frequency transmission circuit, a learning based infrared microprocessor control circuit, an infrared transmission circuit, an infrared receiver circuit, a key-in circuit, a power supply circuit, an LED indicator circuit, a voltage rectification circuit for high frequency circuit, and a high frequency circuit switch. The microprocessor can determine a signal sent from a pressed button, a frequency for high frequency wireless remote control, and calibrating frequency and performing a signal learning. Thereafter, the microprocessor is activated to issue an instruction to a corresponding electrical device through infrared or wireless for effecting a control.
    Type: Application
    Filed: March 15, 2001
    Publication date: September 19, 2002
    Inventor: Taddy Shao
  • Publication number: 20020070877
    Abstract: A measuring transducer with a sensor for converting a detected measured value into a sensor signal. The sensor signal is processed in a signal processing device to form a measuring signal that is transmitted to a central location via a data interface. The data interface is also used as a conduit for signals to parameterize the measuring transducer. The measuring transducer includes a device that provides a simulated measuring signal that can be transmitted to the central location on request via the data interface instead of the detected measured value. Further, a function can be performed on the simulated measuring signal before it is transmitted or a sequence of simulated measuring values can be transmitted corresponding to particular operating conditions.
    Type: Application
    Filed: December 17, 2001
    Publication date: June 13, 2002
    Applicant: SIEMENS AG
    Inventors: Andreas Muhr, Peter Schmith
  • Patent number: 6345203
    Abstract: Magnetic Vector Steering (MVS) and Half-Cycle Amplitude Modulation (HCAM) are novel techniques which enhance the powering and control of multiple arbitrarily oriented implant devices. Together, these techniques enable arbitrarily oriented implants to receive power and command, programming, and control information in an efficient manner that preserves battery life and transmission time while reducing overall implant device bulk. By steering the aggregate magnetic field from a near-orthogonal set of AC-energized coils, selected implants can be powered or communicated with at desired times. Communication with individual implants can also be enhanced through half-cycle amplitude modulation —a technique that allows bit rates up to twice the energizing frequency. Unlike prior art systems, power and data transfer can be realized over the same frequency channel.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: February 5, 2002
    Assignee: North Carolina State University
    Inventors: Jeffrey S. Mueller, H. Troy Nagle, Ronald S. Gyurcsik, Arthur W. Kelley
  • Patent number: 6275144
    Abstract: A method and system for transmitting data using a low frequency offset, differential voltage, OOK transmission technique have been described. According to one embodiment, an analog or digital signal is sent or received and converted, if necessary, into or from serial format onto or out of a power line. This signal is an OOK modulated sinusoidal offset signal with an associated differential voltage. Next, the transmitted signal is input into an additive coupler which serves as an interface to the power-line network. At the far end, an additive decoupler receives the transmission and sends the frequency out to the designated amplifiers to provide the needed voltages to activate the OOK detection system. This system uses current detection that is activated every time the designated OOK signal frequency is received. Further, the OOK signal is decoded and information split off to the designated leads.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: August 14, 2001
    Assignee: TeleNetwork, Inc.
    Inventor: Stephen Roy Rumbaugh
  • Patent number: 6263247
    Abstract: Magnetic Vector Steering (MVS) and Half-Cycle Amplitude Modulation (HCAM) are novel techniques which enhance the powering and control of multiple arbitrarily oriented implant devices. Together, these techniques enable arbitrarily oriented implants to receive power and command, programming, and control information in an efficient manner that preserves battery life and transmission time while reducing overall implant device bulk. By steering the aggregate magnetic field from a near-orthogonal set of AC-energized coils, selected implants can be powered or communicated with at desired times. Communication with individual implants can also be enhanced through half-cycle amplitude modulation—a technique that allows bit rates up to twice the energizing frequency. Unlike prior art systems, power and data transfer can be realized over the same frequency channel.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: July 17, 2001
    Assignee: North Carolina State University
    Inventors: Jeffrey S. Mueller, H. Troy Nagle, Ronald S. Gyurcsik, Arthur W. Kelley
  • Patent number: 6239571
    Abstract: A resolver comprises excitation windings for receiving excitation signals and a detection winding for outputting a detection signal. Displacement of a passive member provided with the excitation windings or the detection winding is detected on the basis of the detection signal which varies with the displacement of the passive member. A modulated signal obtained through modulation of a high-frequency signal by an excitation signal is input to each of the excitation windings, and a detection signal is obtained through demodulation of a modulated signal output from the detection winding. Since the modulated signal obtained through modulation (amplitude modulation) of the high-frequency signal by means of the excitation signal is applied to the excitation windings, the number of turns in the excitation and the detection windings can be reduced.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: May 29, 2001
    Inventor: Shiro Shimahara
  • Patent number: 6239722
    Abstract: A communication system transmits data between a plurality of locations. The communication system is suitable for use by a utility provider to monitor a plurality of metering devices from a remote location. The communication system in accordance with use by a utility provider to monitor metering devices comprises a control for at least receiving data, a plurality of metering devices arranged in a defined number of metering groups for transmitting data associated with an amount of usage of a utility, and a defined number of concentrators, each operably connected to the control and one metering group for transmission of data between the control and plurality of metering devices.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: May 29, 2001
    Assignee: CIC Global, LLC
    Inventors: Laurence Jay Colton, Douglas D. Faith, Richard David Rioboli, Jonathan Peter Worman
  • Patent number: 6225917
    Abstract: A probe for measuring an electromagnetic field is described. A sensing element senses the electromagnetic field and generates a sensing signal indicative thereof. The sensing signal is characterized by a first modality. First conversion circuitry coupled to the sensing element converts the sensing signal to a second modality. A transmission medium coupled to the first conversion circuitry transmits the sensing signal in the second modality. Measurement circuitry coupled to the transmission medium receives the sensing signal in the second modality and generates measurement data corresponding to the electromagnetic field.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: May 1, 2001
    Assignee: Siemens Information and Communication Networks, Inc.
    Inventor: H. Stephen Berger
  • Patent number: 6181258
    Abstract: A receiver which is capable of receiving in parallel data transmitted at arbitrary frequencies within a radio channel includes: a radio frequency (RF) front end to convert an RF signal to a digitized signal; a Fast Fourier Transform (FFT) generator coupled to the RF front-end to separate the digitized signal into a plurality of sub-channels; a bank of phase locked loops (PLLs) coupled to the FFT generator, each PLL operating on a sub-channel with a sub-channel center; and a flag detector coupled to the bank of PLLs to detect variations from the sub-channel center and to recover the usage data transmitted from the end-point.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: January 30, 2001
    Assignee: CellNet Data Systems, Inc.
    Inventors: Andrew Gordon Summers, Clive Russell Irving, Gregory Vincent Luxford