Patents by Inventor Aleksandr Grigorjev

Aleksandr Grigorjev 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 of packet transmission and reception of quadrature amplitude modulated signals in a frequency hopping radio system
    Patent number: 8275017
    Abstract: The invention achieves carrier and clock frequency synchronization in QAD packet communications systems. The invention involves using frequency-hopping radio systems that use pseudo-noise data sequences to mark the beginning of data transmissions and carrier frequency switches. The invention involves transmitting in each of the quadrature channels at an initial carrier frequency a first signal over consecutive time intervals and after transmitting the first signal, transmitting in each of the quadrature channels at a second carrier frequency a second signal over consecutive time intervals.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: September 25, 2012
    Assignee: Modesat Communications OU
    Inventors: Leonid Letunov, Aleksandr Grigorjev
  • Method and system for creating quadrature modulation signal constellations with arbitrary spectral efficiency
    Patent number: 8218679
    Abstract: Methods, systems, transmitters, and receivers implement and use Quadrature Amplitude Modulation QAM2N modulation types and constellations, where N is a real number, e.g., 1.5; 1.33; 2.5; 3.5. The methods, systems, transmitters, and receivers use constellations with the number of points on the circle not equal to a power of two, sending QAM signals of zero power together with other QAM signals, and/or sending sequences of QAM signals of different types.
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: July 10, 2012
    Assignee: Modesat Communications OÜ
    Inventors: Leonid Letunov, Aleksandr Grigorjev
  • Method of packet transmission and reception of Quadrature Amplitude Modulated signals in a frequency hopping radio system
    Publication number: 20100195701
    Abstract: A method to decrease the amount of time required to achieve carrier and clock frequency synchronization in QAD packet communications systems including frequency-hopping radio systems using pseudo-noise data sequences to mark the beginning of data transmissions and carrier frequency switches.
    Type: Application
    Filed: February 5, 2010
    Publication date: August 5, 2010
    Applicant: MODESAT COMMUNICATIONS OU
    Inventors: Leonid Letunov, Aleksandr Grigorjev
  • Method and system for creating quadrature modulation signal constellations with arbitrary spectral efficiency
    Publication number: 20090232253
    Abstract: Methods, systems, transmitters, and receivers implement and use Quadrature Amplitude Modulation QAM2N modulation types and constellations, where N is a real number, e.g., 1.5; 1.33; 2.5; 3.5. The methods, systems, transmitters, and receivers use constellations with the number of points on the circle not equal to a power of two, sending QAM signals of zero power together with other QAM signals, and/or sending sequences of QAM signals of different types.
    Type: Application
    Filed: March 17, 2009
    Publication date: September 17, 2009
    Applicant: MODESAT COMMUNICATIONS OU
    Inventors: Leonid Letunov, Aleksandr Grigorjev