Patents by Inventor James L. Richards

James L. Richards has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040135719
    Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.
    Type: Application
    Filed: January 5, 2004
    Publication date: July 15, 2004
    Applicant: TIME DOMAIN CORPORATION
    Inventors: James L. Richards, Larry W. Fullerton, David C. Meigs, Randall S. Stanley, Ivan A. Cowie
  • Patent number: 6763057
    Abstract: An apparatus and method for communicating information using an ultra wideband impulse radio transmitter and receiver is disclosed. The method includes the steps of generating and transmitting a series of time-modulated pulses, each pulse delayed by one of four predetermined time delay periods and representative of at least two data bits of information, and receiving and demodulating the series of time-modulated pulses to estimate the data bits associated with each pulse. The apparatus includes an impulse radio transmitter and an impulse radio receiver. The transmitter transmits the series of time-modulated pulses and includes a transmitter time base, a time delay modulator, a code time modulator, an output stage, and a transmitting antenna. The receiver receives and demodulates the series of time-modulated pulses using a receiver time base and two correlators, one correlator designed to operate after a pre-determined delay with respect to the other correlator.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: July 13, 2004
    Assignee: Time Domain Corporation
    Inventors: Larry W. Fullerton, James L. Richards, Ivan A. Cowie, Vernon R. Brethour
  • Patent number: 6710736
    Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.
    Type: Grant
    Filed: June 2, 2003
    Date of Patent: March 23, 2004
    Assignee: Time Domain Corporation
    Inventors: Larry W. Fullerton, James L. Richards
  • Patent number: 6700538
    Abstract: An impulse radio system estimates a separation distance between an impulse radio transmitter and an impulse radio receiver. The system includes an impulse transmitter that transmits an impulse signal having an ultra-wideband frequency characteristic. An impulse receiver spaced from the transmitter receives the transmitted impulse signal and measures a signal strength of the received impulse signal. The receiver estimates the separation distance based on the measured signal strength. The receiver classifies a signal propagational/multipath environment using the received impulse signal, and then selects a radio propagation path loss model corresponding to a classified multipath environment. The receiver translates the measured signal strength to a separation distance based on the selected radio propagation path loss model.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: March 2, 2004
    Assignee: Time Domain Corporation
    Inventor: James L. Richards
  • Publication number: 20040027270
    Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.
    Type: Application
    Filed: June 2, 2003
    Publication date: February 12, 2004
    Inventors: Larry W. Fullerton, James L. Richards
  • Patent number: 6674396
    Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: January 6, 2004
    Assignee: Time Domain Corporation
    Inventors: James L. Richards, Larry W. Fullerton
  • Patent number: 6671310
    Abstract: A method for positioning pulses over time (via a time layout) applies time-hopping codes having pre-defined characteristics. The time layout can be sequentially subdivided into at least first and second time components that have the same or different sizes. The method applies a first time-hopping code having first pre-defined properties to the first time component and a second time-hopping code having second pre-defined properties to the second time component. The pre-defined properties may relate to the auto-correlation property, the cross-correlation property, and spectral properties, as examples. The codes can be used to specify subcomponents within a frame, and positions (range-based, or discrete) within the subcomponents, where the pulses are positioned.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: December 30, 2003
    Assignee: Time Domain Corporation
    Inventors: James L. Richards, Mark D. Roberts, Marcus H. Pendergrass, Larry W. Fullerton
  • Publication number: 20030232612
    Abstract: The present invention relates to the conversion of signals from RF to baseband using transition functions, or edge functions. These functions typically transition from positive to negative, or from negative to positive, synchronously with the transition of the received pulse signal, effecting detection essentially by synchronously rectifying a signal cycle of the received pulse, producing a net signal at baseband that can be further processed to detect modulation according to the modulation format. It is further disclosed how to configure these systems for optimal reception with a filter optimized for a given detect signal function. Generalizations of the matched filter embodiment lead to further embodiments employing alternative detection functions. Also disclosed is a two-stage version which applies a decode signal to the rectified signal. This step can be performed by a single correlator or by a plurality of correlators in parallel.
    Type: Application
    Filed: June 14, 2002
    Publication date: December 18, 2003
    Inventors: James L. Richards, Larry W. Fullerton
  • Publication number: 20030197643
    Abstract: A system and a method for position determination by impulse radio using a first transceiver having a first clock providing a first reference signal and a second transceiver placed spaced from the first transceiver. The system determines the position of the second transceiver. The second transceiver has a second clock that provides a second reference signal. A first sequence of pulses are transmitted from the first transceiver. The first sequence of pulses are then received at the second transceiver and the second transceiver is then synchronized with the first sequence of pulses. A second sequence of pulses are transmitted from the second transceiver. The first transceiver receives the second sequence of pulses and the first transceiver is synchronized with the second sequence of pulses. A delayed first reference signal is generated in response to the synchronization with the second sequence of pulses.
    Type: Application
    Filed: May 20, 2003
    Publication date: October 23, 2003
    Inventors: Larry W. Fullerton, James L. Richards, Ivan A. Cowie
  • Patent number: 6636566
    Abstract: A coding method for a pulse transmission system specifies temporal and/or non-temporal pulse characteristics according to temporal and/or non-temporal characteristic value layouts having one or more allowable and non-allowable regions. The method generates codes having predefined properties. The method generates a pulse train by mapping codes to the characteristic value layouts, where the codes satisfy predefined criteria. In addition, the predefined criteria can limit the number of pulse characteristic values within a non-allowable region. The predefined criteria can be based on relative pulse characteristic values. The predefined criteria can also pertain to spectral properties and to correlation properties. The predefined criteria may pertain to code length and to the number of members of a code family. The pulse train characteristics may pertain to a subset of the pulse train.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: October 21, 2003
    Assignee: Time Domain Corporation
    Inventors: Mark D. Roberts, Marcus H. Pendergrass, Larry W. Fullerton, James L. Richards
  • Patent number: 6636567
    Abstract: A code specifies characteristics of pulses transmitted and received by an impulse transmission system. The invention provides methods for defining non-allowable regions within pulse characteristic value range layouts enabling non-allowable regions to be considered when generating a code. Various approaches are used to define non-allowable regions based either on the pulse characteristic value range layout or on characteristic values of one or more other pulses. Various permutations accommodate differences between temporal and non-temporal pulse characteristics. Approaches address characteristic value layouts specifying fixed values and characteristic value layouts specifying non-fixed values. When generating codes to describe pulses, defined non-allowable regions within pulse characteristic value layouts are considered so that code element values do not map to non-allowable pulse characteristic values.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: October 21, 2003
    Assignee: Time Domain Corporation
    Inventors: Mark D. Roberts, Marcus H. Pendergrass, Larry W. Fullerton, James L. Richards
  • Patent number: 6636573
    Abstract: A frame reference signal is produced as a function of a clock signal. A first timing generator generates a coarse timing signal having a nominal period and a transition occurring at a precise temporal position with respect to the nominal period. The nominal period is a function of the frame reference signal. The temporal position is a function of a first input timing command and the clock signal. A second timing generator generates at least one fine timing transition as a function of a second input timing command and the clock signal. A combiner circuit uses the coarse timing signal to select one of the at least one fine timing transitions to output a precise timing signal, wherein the precise timing signal has a high temporal precision with respect to the frame reference signal.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: October 21, 2003
    Assignee: Time Domain Corporation
    Inventors: James L Richards, Preston Jett, Larry W Fullerton, Lawrence E Larson, David A Rowe
  • Publication number: 20030194979
    Abstract: A method for power control in an ultra wideband impulse radio system includes: (a) transmitting an impulse radio signal from a first transceiver; (b) receiving the impulse radio signal at a second transceiver; (c) determining at least one performance measurement of the received impulse radio signal; and (d) controlling output power of at least one of the first transceiver and the second transceiver in accordance with the at least one performance measurement.
    Type: Application
    Filed: April 8, 2003
    Publication date: October 16, 2003
    Inventors: James L. Richards, Larry W. Fullerton, Ivan A. Cowie
  • Patent number: 6611234
    Abstract: A system and a method for position determination by impulse radio using a first transceiver having a first clock providing a first reference signal and a second transceiver placed spaced from the first transceiver. The system determines the position of the second transceiver. The second transceiver has a second clock that provides a second reference signal. A first sequence of pulses are transmitted from the first transceiver. The first sequence of pulses are then received at the second transceiver and the second transceiver is then synchronized with the first sequence of pulses. A second sequence of pulses are transmitted from the second transceiver. The first transceiver receives the second sequence of pulses and the first transceiver is synchronized with the second sequence of pulses. A delayed first reference signal is generated in response to the synchronization with the second sequence of pulses.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: August 26, 2003
    Assignee: Time Domain Corporation
    Inventors: Larry W. Fullerton, James L. Richards, Ivan A. Cowie
  • Publication number: 20030147480
    Abstract: A system and method are provided that can detect any part of a multipath impulse radio signal. More specifically, the method compares a template pulse train and the multipath impulse radio signal to obtain a comparison result. The system performs a threshold check on the comparison result. If the comparison result passes the threshold check, the system locks onto any part of the multipath impulse radio signal including a direct path part and at least one multipath reflection part. The system may also perform a quick check, a sychronization check, and/or a command check of the multipath impulse radio signal.
    Type: Application
    Filed: February 3, 2003
    Publication date: August 7, 2003
    Applicant: Time Domain Corporation
    Inventors: James L. Richards, Mark D. Roberts
  • Publication number: 20030144011
    Abstract: A System and Method for Person or Object Position Location Utilizing Impulse Radio, comprising a plurality of reference impulse radios; an object or person to be tracked having a mobile impulse radio associated therewith; an architecture with an associated positioning algorithm associated with said plurality of impulse radio reference radios and said mobile impulse radio; and display means for displaying the position of the person or object whose position is to be determined.
    Type: Application
    Filed: November 18, 2002
    Publication date: July 31, 2003
    Inventors: James L. Richards, Larry W. Fullerton, Donald A. Kelly, David C. Meigs, Timothy T. Payment, James S. Finn, William J. Tucker, William D. Welch
  • Publication number: 20030128783
    Abstract: A precision timing generator includes a combiner that provides a timing signal by combining a coarse timing signal and a fine timing signal derived from a phase-shifted sinusoidal signal that has a desired phase shift. The coarse timing generator generates the coarse timing signal from a clock signal and a timing command input. The fine timing generator includes a sinusoidal-signal generator that receives the clock signal and generates a sinusoidal signal. The fine timing generator also includes a phase shifter that receives the sinusoidal signal and the timing command input and shifts the phase of the sinusoidal signal based on the timing input to generate the phase shifted sinusoidal signal.
    Type: Application
    Filed: December 26, 2002
    Publication date: July 10, 2003
    Applicant: Time Domain Corporation
    Inventors: James L. Richards, Preston L. Jett, Larry W. Fullerton, Lawrence E. Larson, David A. Rowe
  • Publication number: 20030108133
    Abstract: A TR-UWB receiver receives TR pulses comprising reference and data pulses separated by a delay, D. The receiver includes a multiplier having a first input for inputting a data pulse. A delay circuit delays a reference pulse by D and inputs the delayed reference pulse to a second input of the multiplier. An integrator integrates the output of the multiplier. A baseband signal resulted from integrating the output of the multiplier is demodulated for recovering the communicated data. A gating circuit limits the noise captured prior to the integrator, in response to a gating signal generated during a time fixed or variable gating time interval. Also, a feedback circuit combines forward and feedback noise non-coherently to improve received signal-to-noise ratio.
    Type: Application
    Filed: October 10, 2002
    Publication date: June 12, 2003
    Inventor: James L. Richards
  • Publication number: 20030106249
    Abstract: A mounting for a sheet that has a bead about its periphery includes frame members forming a rectangle with each frame member including mutually parallel multiple engagement surfaces defined on ribs. An elongate retainer includes an elongate flange with an interlocking surface which can selectively interlock with any one of the engagement surfaces on the frame. The frame also has a frame rail having a rail surface that faces away from a retainer rail surface on a rail of the retainer. A tool including pinch rollers squeeze the rail surfaces toward one another to place the sheet material held by the retainer in tension while the interlocking surface is engaged with the appropriate engagement surface.
    Type: Application
    Filed: January 8, 2003
    Publication date: June 12, 2003
    Applicant: EPIC MEDIA GROUP LLC
    Inventors: James L. Richards, Marvin A. Smith
  • Patent number: 6577691
    Abstract: A precision timing generator includes a combiner that provides a timing signal by combining a coarse timing signal and a fine timing signal derived from a phase-shifted sinusoidal signal that has a desired phase shift. The coarse timing generator generates the coarse timing signal from a clock signal and a timing command input. The fine timing generator includes a sinusoidal-signal generator that receives the clock signal and generates a sinusoidal signal. The fine timing generator also includes a phase shifter that receives the sinusoidal signal and the timing command input and shifts the phase of the sinusoidal signal based on the timing input to generate the phase shifted sinusoidal signal.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: June 10, 2003
    Assignee: Time Domain Corporation
    Inventors: James L. Richards, Preston L. Jett, Larry W. Fullerton, Lawrence E. Larson, David A. Rowe