• COMPARISON OF ALAMOUTI AND DIFFERENTIAL SPACE-TIME CODES FOR AERONAUTICAL TELEMETRY DUAL-ANTENNA TRANSMIT DIVERSITY

      Jensen, Michael A.; Rice, Michael D.; Anderson, Adam L.; Brigham Young University (International Foundation for Telemetering, 2004-10)
      The placement of two antennas on an air vehicle is one possible practice for overcoming signal obstruction created by vehicle maneuvering during air-to-ground transmission. Unfortunately, for vehicle attitudes where both antennas have a clear path to the receiving station, this practice also leads to self-interference nulls, resulting in dramatic degradation in the average signal integrity. This paper discusses application of unitary space-time codes such as the Alamouti transmit diversity scheme and unitary differential space-time codes to overcome the self-interference effect observed in such systems.
    • ORTHOGONAL DUAL-ANTENNA TRANSMIT DIVERSITY FOR SOQPSK IN AERONAUTICAL TELEMETRY CHANNELS

      Jensen, Michael A.; Rice, Michael D.; Nelson, Thomas; Anderson, Adam L.; Brigham Young University (International Foundation for Telemetering, 2004-10)
      Transmit diversity schemes such as the Alamouti space-time code have been shown to be viable candidates to enable robust dual-antenna transmission from maneuvering air vehicles. However, due to the complicated structure of shaped offset quadrature phase shift keying (SOQPSK) modulation, the Alamouti approach has not been applicable to SOQPSK systems. This paper develops a precoding and detection algorithm which allows implementation of dual-antenna Alamouti signaling for SOQPSK modulation. Performance simulations demonstrate the performance of the scheme for a realistic flight scenario.