Patents Assigned to L3 Communication
  • Patent number: 6738314
    Abstract: An autonomous mine detection and neutralization system including a motorized underwater vehicle having a guidance control component, and a vehicle positioning system attached to the vehicle via a communications cable. The system also includes a buoyant surface unit comprising a protective housing surrounding an interior chamber, a positive buoyancy buoy attached to the housing, an antenna system attached to the housing, and a radio transmitter and receiver system positioned within the chamber, which radio transmitter and receiver system is electrically attached to the vehicle positioning system and the antenna system. The mine detection system is launched into a body of water from an air craft or surface vessel. The vehicle then proceeds to an underwater target on its own, relaying navigation data and imagery through a communications cable to a surface unit which relays the information over a radio frequency link to a remote user.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: May 18, 2004
    Assignee: L3 Communications Corporation
    Inventors: Michael A. Teeter, Kip Harrington
  • Publication number: 20040065461
    Abstract: A hardened voyage data recorder includes two subsystems: a removable non-volatile memory and a base containing electronics and firmware for communicating with data sensing systems and for accessing the memory. According to the invention, the memory is protected in a “boiler” and the electronics includes an ETHERNET interface for connecting to shipboard data acquisition devices. The firmware is preferably configured via web pages. A communications protocol for communicating with the recorder is also disclosed.
    Type: Application
    Filed: September 24, 2003
    Publication date: April 8, 2004
    Applicant: L3 Communications Corporation
    Inventors: Margaret Browning, Gregory W. Purdom, Andrew Zarling
  • Publication number: 20040047401
    Abstract: A method and system for determining Psuedo-Noise (PN) composite phase is provided. The method includes providing at least three relatively prime PN component codes and partially correlating a received PN composite encoded signal with one of the PN component codes. The method also includes partially correlating the received PN composite encoded signal with a second one of the PN component codes while maintaining phase alignment of the first partially phase aligned PN code through the use of normalized autonomous phase numbers (NAPNs). The received PN composite encoded signal is then phase aligned with a receiver PN composite code phase in steps of epoch lengths of the partially phase aligned PN component codes.
    Type: Application
    Filed: September 11, 2002
    Publication date: March 11, 2004
    Applicant: L3 Communications Corporation
    Inventors: Merle L. Keller, Vaughn L. Mower, Dale D. Fonnesbeck
  • Patent number: 6697381
    Abstract: A packet data frame and system for transmitting and receiving the packet data frame. The packet data frame comprises a data signal and a header appended to the data signal. The header includes information corresponding to a length of the data signal used by the data communication system to transmit and receive the data signal in a contiguous sequence.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: February 24, 2004
    Assignee: L3 Communications
    Inventors: Michael S. Talbot, J. Kendall Anderson, Lori K. Eckles
  • Patent number: 6646696
    Abstract: A backlit LCD display apparatus includes an LCD display panel, a light source for backlighting the LCD display panel, a loss-less polarizing element positioned between the backlight and the LCD display panel, and a dimmer device in the form of a twisted nematic LCD cell positioned between the polarizing element, and the LCD display panel
    Type: Grant
    Filed: May 5, 2000
    Date of Patent: November 11, 2003
    Assignee: L3 Communications Corporation
    Inventor: Kevin L. Walsh
  • Patent number: 6643678
    Abstract: An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver can include a Doppler correction circuit, which permits correlation data with frequency shift in the code to be non-coherently integrated among relatively fewer addresses or tap positions in memory. One receiver includes a Doppler offset generator that can advantageously offset a time index used to address a tap position in a non-coherent memory to compensate for code drift in a code with a frequency offset. The amount of offset is computed by accumulating clock cycles of a clock signal that is related to the frequency offset computed by the DFT or FFT frequency bin. The offset aligns a correlation peak in the received code such that the correlation peak can be accumulated in relatively fewer tap positions or addresses.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: November 4, 2003
    Assignee: Interstate Electronics Corporation, a division of L3 Communications Corporation
    Inventors: Robert J. Van Wechel, Michael F. McKenney
  • Patent number: 6567833
    Abstract: An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver advantageously detects frequency shifts using a compact parallel process hardware implementation of a Discrete Fourier Transform (DFT). The simultaneous detection of multiple frequencies allows the receiver to search the frequency range of the transmitted signal in larger increments of frequency, thereby increasing the speed of acquisition. One receiver does not use coherent integration before computation of the transform and advantageously maintains a flat frequency response. The flat frequency response of the DFT circuit enables searching of multiple frequency offsets without CPU intensive processing to compensate for frequency response variations. A receiver can include a Doppler correction circuit, which permits correlation data with frequency shift in the code to be non-coherently integrated among relatively fewer addresses or tap positions in memory.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: May 20, 2003
    Assignee: Interstate Electronics Corporation, a division of L3 Communications Corp.
    Inventors: Robert J. Van Wechel, Michael F. McKenney
  • Publication number: 20030078027
    Abstract: A surface mount, even harmonic mixer is preferably used in point-to-multipoint millimeter wave transceivers. The mixer includes an anti-parallel series arrangement of diodes in one or more ring quads to increase the input 1 dB compression point and third-order input intercept point (IP3), while maintaining the benefits inherent with even harmonic mixing.
    Type: Application
    Filed: October 18, 2001
    Publication date: April 24, 2003
    Applicant: L3 Communications Corporation
    Inventor: Joseph L. Merenda
  • Patent number: 6466958
    Abstract: An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver advantageously detects frequency shifts using a compact parallel process hardware implementation of a Discrete Fourier Transform (DFT). The simultaneous detection of multiple frequencies allows the receiver to search the frequency range of the transmitted signal in larger increments of frequency, thereby increasing the speed of acquisition. One receiver does not use coherent integration before computation of the transform and advantageously maintains a flat frequency response. The flat frequency response of the DFT circuit enables searching of multiple frequency offsets without CPU intensive processing to compensate for frequency response variations. A receiver can include a Doppler correction circuit, which permits correlation data with frequency shift in the code to be non-coherently integrated among relatively fewer addresses or tap positions in memory.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: October 15, 2002
    Assignee: Interstate Electronics Corporation, a division of L3 Communications Corporation
    Inventors: Robert J. Van Wechel, Michael F. McKenney
  • Patent number: 6442690
    Abstract: Apparatus and methods for remotely rekeying a cryptographic device are disclosed. A method according to the invention includes associating a preliminary certificate with the device, generating a device certificate associated with the device, determining whether a certificate stored in the device is the preliminary certificate associated with the device, and if the certificate stored in the device is the preliminary certificate associated with the device, then securely loading the device certificate into the device. Apparatus for remotely rekeying a cryptographic device includes a computer readable medium having stored thereon computer executable instructions for performing a method according to the invention.
    Type: Grant
    Filed: October 21, 1999
    Date of Patent: August 27, 2002
    Assignee: L3-Communications Corporation
    Inventors: James L. Howard, Jr., Pennington J. Hess, James A. MacStravic
  • Patent number: 6410995
    Abstract: The invention provides a back up power supply for avionics equipment that can be installed in existing avionics equipment trays without having to rewire the aircraft. According to a preferred embodiment of the invention (described for illustrative purposes in the context of providing a power supply back up for a cockpit voice recorder (CVR)), the power supply/CVR combination is retrofit in an existing CVR rack. The power supply is modular; removable/replaceable; and is “independent” relative to the main aircraft power source and wiring. The modular power supply is designed to fit into a conventional CVR tray; and the modular power supply is designed to accept an existing CVR.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: June 25, 2002
    Assignee: L3 Communications Corporation
    Inventors: Charles J. Grouse, Mart D. Dismukes, Gregory W. Purdom
  • Patent number: 6400649
    Abstract: An improved transducer arrangement for low frequency sonar projectors that convert electric signals to mechanically generated acoustic signals. In one embodiment the arrangement has both a convex flextensional transducer and a concave flextensional transducer. An open side of the convex transducer is attached to an open side of the concave transducer by an intermediate bulkhead which closes each of the attached open sides. An end plate is attached to another open side of the convex transducer and another end plate is attached to another open side of the concave transducer such that the end plates close the attached open sides. In another embodiment, transducer assembly has a convex transducer having end plates and a concave transducer having end plates. Either one of the endplates of the concave transducer is attached to one of the endplates of the convex transducer, or an endplate of the concave transducer is also an endplate of the concave transducer.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: June 4, 2002
    Assignee: L3 Communications Corporation
    Inventors: Colin W. Skinner, Qi-Chang Xu
  • Patent number: 6400235
    Abstract: A coupler includes one or more conductors and a support structure for the conductors within the coupler. The conductors are inserted through oblong holes in the support structure while the support structure is in an assembling position. When the support structure is tilted from the assembling position to a securing position, which is in a direction away from normal to a longitudinal axis of the conductors, the external surfaces of the conductors are engaged by the support structure at the oblong holes. Typically, a removable cover of the coupler exerts a downward force, which deflects opposite outer edges of the support structure to maintain the support structure in the securing position. The spacing between the conductors is maintained substantially constant over time, temperature, and handling while the support structure is in the securing position.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: June 4, 2002
    Assignee: L3 Communications Corporation
    Inventor: Henry Perez
  • Patent number: 6341661
    Abstract: A compact, modular sonar assembly for use on the bow of a ship having separate transmitting and receive arrays confined within a single acoustic housing. The narrow and compact design fits much better into the hydrodynamically desirable bulbous bow deign than the typical bow dome sonar design and achieves good performance at a low cost with reduced size and weight.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: January 29, 2002
    Assignee: L3 Communications Corporation
    Inventors: Ernest Theodore Bick, Merrill E. Fife, Scott A. Hudson
  • Publication number: 20010040525
    Abstract: Apparatus and methods for processing RF signals are disclosed. A method according to the invention includes receiving a set of time domain energy samples representing signal energy present in an RF spectrum, transforming the set of time domain energy samples into a set of frequency domain power samples, determining from the set of frequency domain power samples whether a signal of interest is present in the RF spectrum, and forwarding to a follow on system a subset of the set of frequency domain power samples, wherein the subset corresponds to the signal of interest. Transforming the time domain samples can include dividing the set of time domain energy samples into a plurality of N windows, each of which is associated with a predefined window period, and performing an FFT on each said window to generate a set of K frequency bins, wherein each frequency bin has a value based on energy present in a predefined frequency band during the corresponding window period.
    Type: Application
    Filed: May 30, 2001
    Publication date: November 15, 2001
    Applicant: L3 Communications Corporation
    Inventors: Joseph F. Springer, Conrad H. Haber
  • Patent number: 6285628
    Abstract: The invention pertains a bathymetric sonar system involving a single swept transmit beam projector system which compensates for ship attitude and positioning changes. A sonar transducer array has a matrix of acoustic projector elements arranged in a plurality of substantially parallel rows and a plurality of substantially parallel columns; and means for causing each of the projector elements to generate an acoustic signal at a frequency and phase independently from each other projector element. Preferably the transducer array is operated by causing the projector elements to generate an acoustic signal at a frequency and phase independently from each other projector element, at a frequency and phase which is initially the same as the frequency and phase of each other element in its column and such that the frequency and phase of the projector elements in each column is different from each other column. Thus a single swept beam is projected toward the ocean floor.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: September 4, 2001
    Assignee: L3 Communications Corporation
    Inventor: Kenneth C. Kiesel
  • Patent number: 6278658
    Abstract: An improved transducer arrangement for low frequency sonar projectors that convert electric signals to mechanically generated acoustic signals. In one embodiment the arrangement has both a convex flextensional transducer and a concave flextensional transducer. An open side of the convex transducer is attached to an open side of the concave transducer by an intermediate bulkhead which closes each of the attached open sides. An end plate is attached to another open side of the convex transducer and another end plate is attached to another open side of the concave transducer such that the end plates close the attached open sides. In another embodiment, transducer assembly has a convex transducer having end plates and a concave transducer having end plates. Either one of the endplates of the concave transducer is attached to one of the endplates of the convex transducer, or an endplate of the concave transducer is also an endplate of the concave transducer.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: August 21, 2001
    Assignee: L3 Communications Corporation
    Inventors: Colin W. Skinner, Qi-Chang Xu
  • Patent number: 6275448
    Abstract: A generally cylindrical hydrophone configuration provides compensation for longitudinal accelerations by placing four identical solid piezoelectric transducer elements along its axis with each transducer element being bonded to a head member, two of which are located generally centrally of the cylindrical housing and fastened thereto and two of which are located near the outside edges of the housing and having slight clearance therewith. Flexible polyurethane boots are clamped to the ends of the housing. The volumes between the centrally disposed and outer transducer head members and between the outer head members and the boots are filled with methyl silicon fluid. Each head member is electrically connected to one side of the electrical output, and the junction between the transducer members is connected to the opposite side, both sides being wired to an electrical contact plate located between the two centrally disposed transducer head members, this volume being filled with electrical potting material.
    Type: Grant
    Filed: December 12, 1977
    Date of Patent: August 14, 2001
    Assignee: L3 Communication
    Inventors: Elmore Kittower, James W. Pell, Jr.
  • Patent number: 6275183
    Abstract: Apparatus and methods for reducing data flow through a signal processing system are disclosed. A method according to the invention includes receiving a set of tags from an input system, where each tag is associated with a pulse and includes a pulse characterization parameter that characterizes the associated pulse. The pulse characterization parameter can be based on, for example, pulse center frequency, duration, or angle of arrival. The method includes identifying a subset of tags from the set of tags, where each tag in the subset includes a predefined value of the pulse characterization parameter. The subset of tags can be identified by histogramming the set of tags based on the pulse characterization parameter. If the number of tags in the subset exceeds a threshold number, then the number of tags from the subset that is forwarded through the system is limited to no more than the threshold number of tags.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: August 14, 2001
    Assignee: L3-Communications Corporation
    Inventor: Joseph F. Springer
  • Patent number: 6266418
    Abstract: An encryption device for a telephone having a handset and a base unit is disclosed. The device includes a handset interface, a first converter, an encryption processor, a second converter, and a host interface. The handset interface receives analog output signals from the handset. The first converter converts the analog output signals into digital output signals. The encryption processor includes a compressor, a key manager, an encryptor, and a modulator. The key manager generates key material for encrypting the digital output signals. The compressor compresses the digital output signals, the encryptor encrypts the digital output signals based on the key material, and the modulator modulates the encrypted digital output signals. The second converter converts the encrypted digital output signals into encrypted analog output signals. The host interface receives the encrypted analog output signals from the encryption processor, and forwards the encrypted analog output signals to the base unit.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: July 24, 2001
    Assignee: L3-Communications Corporation
    Inventors: Matthew Carter, Frank Costantini, Moishe Kleidermacher, Ellwood McGrogan, Ronald Paraggio