Patents by Inventor Mark A. Birchler

Mark A. Birchler 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).

  • Method for determining desired components of quadrature modulated signals
    Patent number: 5396656
    Abstract: In the following manner, a receiver that receives quadrature modulated signals may determine desired components of the quadrature modulated signals by minimizing effects of transmitted distortion produced by gain, phase, or gain-phase imbalance. A quadrature modulated signal that includes a desired component, a fading component, and a transmitter distortion component is received by the receiver, wherein the transmitter distortion component includes a conjugate component and an imbalance component. The receiver estimates the fading component, the conjugate component, and the imbalance component and determines the desired component based on these estimates and the quadrature modulated signal.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: March 7, 1995
    Assignee: Motorola, Inc.
    Inventors: Steven C. Jasper, Mark A. Birchler
  • Peak to average power ratio reduction methodology for QAM communications systems
    Patent number: 5381449
    Abstract: The ratio of peak power level to average power level in a power amplifier used in a QAM communication system transmitter can be reduced by preselecting magnitudes and phase angles of complex-valued pilot symbols used in multi-channel, N-level QAM.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: January 10, 1995
    Assignee: Motorola, Inc.
    Inventors: Steven C. Jasper, Mark A. Birchler
  • Low splatter peak-to-average signal reduction
    Patent number: 5287387
    Abstract: In order to maintain low-splatter in a peak-to-average reduction for a linear communication system, a method of windowed-clipping is used. When a sample of input signal is determined to be above a predetermined threshold, a signal peak is found and an attenuating window is centered at the peak. The attenuating window is applied to the input signal.
    Type: Grant
    Filed: March 6, 1992
    Date of Patent: February 15, 1994
    Assignee: Motorola, Inc.
    Inventor: Mark A. Birchler
  • Multi-channel TDM communication system slot phase correction
    Patent number: 5241544
    Abstract: In a digital communication system in which pulse-shape filtered sync, pilot, and data symbols, arranged in successive time slots, modulate sub-channel carriers via sub-channel mixers to form sub-channel symbol streams for combination into a composite signal for transmission, deterministic portions of each time slot are rendered identical by determining phase difference of sub-channel carriers and rotating the phase of each sub-channel symbol stream by an amount equal to the phase difference, but with opposite sign.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: August 31, 1993
    Assignee: Motorola, Inc.
    Inventors: Steven C. Jasper, Mark A. Birchler
  • Control strategy for reuse system assignments and handoff
    Patent number: 5170413
    Abstract: Disclosed is a method of selecting a relatively high reliability signal path between a mobile communication unit and a number of possible base sites.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: December 8, 1992
    Assignee: Motorola, Inc.
    Inventors: Garry C. Hess, Mark A. Birchler
  • Maximal ratio diversity combining technique
    Patent number: 5140615
    Abstract: A method for implementing diversity reception to counteract effects of channel fading on a transmitted information signal. In diversity receive paths, estimates of complex channel gain are computed based upon pilot symbols inserted from time to time in the transmitted information symbol stream. Phase corrected and weighted samples from the diversity paths are summed prior to the decision process. The squared magnitudes of the diversity path channel gains are summed to provide the proper threshold adjustment.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: August 18, 1992
    Assignee: Motorola, Inc.
    Inventors: Steven C. Jasper, Mark A. Birchler