Patents by Inventor Paul W. Dent

Paul W. Dent 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: 20040259497
    Abstract: A satellite communications system uses multiple ground stations and one or more satellites for communicating between mobile subscribers and a land-based communications network, such as the PSTN or the Internet. Multiple ground stations geographically dispersed minimize toll charges incurred routing calls from a mobile subscriber through the land network by reducing the need for long-distance calling. Further, because each ground station communicates with a given satellite using the same frequency spectrum, the subscriber capacity of the system increases and/or bandwidth requirements for the communications link between ground stations and satellites may be reduced. The present system uses ground-based beamforming techniques enabling each satellite to transmit signals in multiple transmission beams, each beam supporting one or more mobile subscribers. Each beam may reuse the same frequency spectrum, thereby increasing the number of subscribers supported by each satellite.
    Type: Application
    Filed: July 20, 2004
    Publication date: December 23, 2004
    Inventor: Paul W. Dent
  • Publication number: 20040252667
    Abstract: In CDMA systems, a message to be transmitted is redundantly coded for transmission using a combination of error-correction coding and a spread-spectrum access code. The coded message is modulated to a first radio frequency channel, or band, and also to at least one other frequency channel, which may be either an adjacent or a non-adjacent channel. Other messages for transmission are generated likewise and the signals for transmission on the first channel are summed using a set of weighting factors, with the weighted sum transmitted on the first channel. The same signals are summed for transmission on the at least one other frequency channel, but using weighting factors that have a progressive relative phase rotation compared to their values on the first channel. The sequence of weighting factors used for one signal across the different frequency channels is preferably orthogonal to the sequence of weighting factors used for a different signal.
    Type: Application
    Filed: December 19, 2003
    Publication date: December 16, 2004
    Inventor: Paul W. Dent
  • Patent number: 6831907
    Abstract: A method of broadcasting commercial FM services in a digital format in at least one bitstream comprises time-division multiplexing the bitstream(s) into one or more channels comprising a data frame, and frequency modulating the data frames around a single carrier frequency into a commercial FM broadcast signal. The modulation may comprise GMSK or 8-PSK, and multiple data frame types may be interleaved. The signal is transmitted on a commercial FM broadcast station such that substantially the entire spectrum of the transmission comprises the digital data frames. The bit rate(s) of the digital bitstream(s) may be monitored, and the bitstream(s) may be reallocated to channels in the data frames based on changes in the bit rate(s). Analog and digital formats may be broadcast simultaneously on non-adjacent commercial FM broadcast carrier channels. A receiver is operative to extract and decode content from a digital format FM broadcast signal.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: December 14, 2004
    Assignee: Ericsson Inc.
    Inventors: Rodney A. Dolman, Paul W. Dent
  • Patent number: 6823170
    Abstract: A satellite communications system uses multiple ground stations and one or more satellites for communicating between mobile subscribers and a land-based communications network, such as the PSTN or the Internet. Multiple ground stations geographically dispersed minimize toll charges incurred routing calls from a mobile subscriber through the land network by reducing the need for long-distance calling. Further, because each ground station communicates with a given satellite using the same frequency spectrum, the subscriber capacity of the system increases and/or bandwidth requirements for the communications link between ground stations and satellites may be reduced. The present system uses ground-based beamforming techniques enabling each satellite to transmit signals in multiple transmission beams, each beam supporting one or more mobile subscribers. Each beam may reuse the same frequency spectrum, thereby increasing the number of subscribers supported by each satellite.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: November 23, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Publication number: 20040203468
    Abstract: A wireless communication network processes composite loop-back signals received at one or more network antennas from a plurality of mobile stations, each transmitting an individual, mobile-specific loop-back signal. Using its knowledge of the prior network-transmitted signal(s) from which the mobile stations derive their individual loop-back signals, and its knowledge of the mobile-specific loop-back signal modifications made by each of the mobile stations, the network derives mobile-specific downlink channel information based on processing the composite loop-back signals. That is, use of the mobile-specific loop-back signals enables the network to determine downlink channel estimates as between each participating network antenna and each participating mobile station to be used for transmit signal interference and/or power pre-compensation, for example.
    Type: Application
    Filed: February 14, 2003
    Publication date: October 14, 2004
    Inventors: Paul W. Dent, Kambiz C. Zangi
  • Patent number: 6802001
    Abstract: A method of determining an encryption key used by two or more parties for encrypted communications in a manner that prohibits any of the parties from forcing the final value of the encryption key. The encryption key is determined based on numbers exchanged by the parties using a key generation function, such as the Diffie-Hellman algorithm. To prevent any party from forcing the final value of the encryption key to a desired value, a first party divides its number into a plurality of parts, which are transmitted incrementally to the another. After transmitting a first part, the first party waits for receipt of at least a part of a second exchanged number from another party before the first party transmits the remaining parts of its exchanged number.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: October 5, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Publication number: 20040156443
    Abstract: The invention comprises using beamforming antenna to coherently transmit an information signal to a receiver using two or more directional beams. In one embodiment, the phase and timing of the information signals carried by each directional beams are adjusted such that the signals arrive synchronously at the mobile terminal. Time synchronization may be obtained by delaying signals transmitted on selected directional beams to compensate for different propagation delays, or by preconditioning and filtering the signals using a channel coefficient matrix.
    Type: Application
    Filed: February 10, 2003
    Publication date: August 12, 2004
    Inventor: Paul W. Dent
  • Patent number: 6769062
    Abstract: A method and system for performing cryptographic calculations on a bitstring using secret information. A cipher key is manipulated to obtain a modified cipher key. An indicator word is generated that corresponds to the modified cipher key and includes a plurality of indicator bits. A first product is computed with an insecure processor as a function of the bitstring and the modified cipher key. A second product is computed with a secure processor as a function of the bitstring and the indicator. A final product is then computed as a function of the first and second products.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: July 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Ben Smeets, Michael Kornby, Paul W. Dent
  • Patent number: 6768900
    Abstract: An improved satellite communications system allows for greater spectral efficiency by requiring just two frequencies for wireless communications between a first ground-based station and a second ground-based station via a satellite. Both the first station and the second station use the first frequency to transmit signals to the satellite; the satellite transponds the signals it receives on the first frequency to the second frequency and transmits the signals to the first and second stations on the second frequency. Use of two frequencies in such a manner results in some own-signal interference. The first station preferably stores its outgoing signals in memory and then subtracts out these stored signals to eliminate the its own-signal interference. The second station may likewise store and subtract out its transmissions, but this is not required.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: July 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Tony Ottoson
  • Patent number: 6769060
    Abstract: A method for bilateral identity authentication over a communication channel provides a secure method for authenticating the identity of the communicating parties and establishing a secret key. Each party computes an authentication challenge based on an exchanged value used in a key generation procedure. The authentication challenge is encrypted to the other party's public key. After receiving an encrypted authentication channel from the other party, each party deciphers the authentication challenge and generates an authentication response based on the authentication challenge. The authentication response includes bits that the challenging party cannot predict in advance to prevent fraudulent use of the authentication response by the challenging party or some other third party. After receiving an authentication response from the other party, each party verifies that the expected authentication response was received.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: July 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Nils Rydbeck
  • Patent number: 6768391
    Abstract: Quadrature modulators include a quadrature splitter and a pair of Gilbert Multiplier Cells coupled to the quadrature splitter, each of which is biased in Class-B. The quiescent current bias in the Gilbert Multiplier Cells may be substantially zero. Each of the Gilbert Multiplier Cells may include a pair of cross-coupled, emitter-coupled transistor pairs transistor pairs and a driver circuit that is coupled to at least one of the emitter-coupled transistor pairs and that is biased in Class-B. The driver circuit may include at least one current mirror circuit that is coupled to at least one of the emitter-coupled transistor pairs. The driver circuit also may include at least one current source that selectively applies current to at least one of the emitter-coupled transistor pairs, more specifically by selectively applying current to the at least one current mirror circuit.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: July 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Aristotle Hadjichristos
  • Patent number: 6768389
    Abstract: A quartz crystal oscillator comprises a balanced circuit with a quartz crystal resonator device connected in series resonance across a balanced, low-impedance node within a sustaining amplifier. A phase modulator such as a quadrature modulator is included in the feedback loop to allow programming of the loop phase shift thereby to alter the frequency point on the crystal resonance curve at which the circuit oscillates. The in-phase loop signal is hardlimited while the quadrature loop signal component is not hardlimited with the effect that the frequency control curve slope is more accurately defined. An active neutralization of the crystal's parasitic shunt capacitance is disclosed for obtaining a linear frequency control curve.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: July 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Nikolaus Klemmer
  • Publication number: 20040110506
    Abstract: A receiver receives communication signals on an assigned frequency channel while monitoring the signals received on other frequency channels. A communication processor processes the received communication signals from the current base station while a wideband digitizer processes received filtered signals on the other frequency channels, which correspond to the neighboring base stations. The wideband digitizer generates numerical samples representing the filtered signals in response to a control signal generated by a control processor. The control processor then determines characteristic signals of the frequency channels.
    Type: Application
    Filed: April 23, 2003
    Publication date: June 10, 2004
    Inventor: Paul W. Dent
  • Patent number: 6731763
    Abstract: According to the exemplary embodiments, a voltage or current-controlled oscillator is controlled in frequency by the signal (i.e., voltage or current) from a microphone. The frequency modulated signal is applied to a direct digital discriminator that produces a digital representation of the instantaneous frequency at the desired speech sampling rate. The digital discriminator may be formed, for example, by applying the oscillator signal to a direct phase digitizing circuit along with a reference frequency and calculating a sequence of instantaneous phases of the oscillator relative to the reference frequency. The phase sequence is then applied to a digital phase locked loop (or otherwise numerically differentiated) to generate a sequence of binary words representative of instantaneous frequency and therefore representative of the speech waveform.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: May 4, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Publication number: 20040056728
    Abstract: A quartz crystal oscillator comprises a balanced circuit with a quartz crystal resonator device connected in series resonance across a balanced, low-impedance node within a sustaining amplifier. A phase modulator such as a quadrature modulator is included in the feedback loop to allow programming of the loop phase shift thereby to alter the frequency point on the crystal resonance curve at which the circuit oscillates. The in-phase loop signal is hardlimited while the quadrature loop signal component is not hardlimited with the effect that the frequency control curve slope is more accurately defined. An active neutralization of the crystal's parasitic shunt capacitance is disclosed for obtaining a linear frequency control curve.
    Type: Application
    Filed: September 23, 2002
    Publication date: March 25, 2004
    Inventors: Paul W. Dent, Nikolaus Klemmer
  • Publication number: 20040058653
    Abstract: A transceiver for a code division multiple access communication system comprises a receiver to receive coded information signals and a transmitter to transmit coded information signals. A local oscillator provides a time and frequency reference for the receiver and the transmitter. A timing controller provides timing signals for the receiver and the transmitter. A signal processor decodes received signals to determine a common error associated with the timing controller. A timing correction circuit smoothly adjusts the timing of the coded information signals transmitted by the transmitter responsive to the timing error to reduce the timing error over a desired time interval.
    Type: Application
    Filed: September 23, 2002
    Publication date: March 25, 2004
    Inventor: Paul W. Dent
  • Patent number: 6711218
    Abstract: A system and method for sequence estimation decoding allows a receiver to decode a received signal modulated according to one of plurality of possible modulating methods. In a preferred approach, a sequence estimation decoder detects the modulating method that was applied to the received signal, and adjusts its decoding process accordingly. In this manner, the decoder adjusts its operations to the specific one of the plurality of possible modulating methods used by the transmitting system originating the received signal. In an exemplary application, signals are modulated using either Gaussian Minimum Shift Keying (GMSK) or Offset Quadrature Amplitude Modulation (Offset-QAM), and the decoder adjusts its operations to either one of these modulating methods based on its detection of the particular method used.
    Type: Grant
    Filed: December 6, 2000
    Date of Patent: March 23, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Patent number: 6690798
    Abstract: A method and apparatus is described for transforming a key variable used for scrambling mobile data traffic between a terminal and a network in alternate ways based on a value transmitted to the terminal from the network. Transformation is accomplished by passing portions of the key variable through a series of S-boxes, which provide a mapping between inputs and outputs. The method and apparatus is explained also in the context of a satellite communications system, in which a terminal can be located in a different continent/country from the terminal's home location. Enciphered communication is enabled between the foreign satellite gateway and the roaming terminal after the foreign gateway communicates with the terminal's native gateway. The native gateway transmits one or more cipher variables in the communication. Moreover, the value determining which way to cipher the data traffic can be based on numerous factors, including aspects of the satellite communication system.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: February 10, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Patent number: 6684071
    Abstract: Exemplary embodiments of the present invention describe terminal position location methods and systems. Relative powers of nearby spot beams which are generated by array antennas are determined. For example, powers from six neighboring spot beams relative to a center spot beam within which a mobile station is currently operating, can be measured relative to the power of the center spot beam. Using information from these measurements, the mobile stations position can be determined using, for example, an exponential model of the spot beam pattern.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: January 27, 2004
    Assignee: Ericsson Inc.
    Inventors: Karl J. Molnar, Paul W. Dent
  • Patent number: 6680928
    Abstract: In CDMA systems, a message to be transmitted is redundantly coded for transmission using a combination of error-correction coding and a spread-spectrum access code. The coded message is modulated to a first radio frequency channel, or band, and also to at least one other frequency channel, which may be either an adjacent or a non-adjacent channel. Other messages for transmission are generated likewise and the signals for transmission on the first channel are summed using a set of weighting factors, with the weighted sum transmitted on the first channel. The same signals are summed for transmission on the at least one other frequency channel, but using weighting factors that have a progressive relative phase rotation compared to their Values on the first channel. The sequence of weighting factors used for one signal across the different frequency channels is preferably orthogonal to the sequence of weighting factors used for a different signal.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: January 20, 2004
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent