• LDPC CODED APSK FOR AERONAUTICAL TELEMETRY

      Perrins, Erik; Pathak, Sumant; Univ Kansas, Electrical Engineering and Computer Science (International Foundation for Telemetering, 2017-10)
      This paper presents the performance of capacity-approaching low-density parity check (LDPC) coded amplitude phase shift keying (APSK) over aeronautical telemetry channels. We show the bit-error rate results for code-rates of 1/2, 2/3, 3/4, and 4/5 with 16 and 32 point constellations. Results are presented and compared between an optimal and sub-optimal reduced-complexity demodulating system. We also compare the results with SOQPSK-TG under similar channel conditions and provide an estimate of backoff needed for implemention with power amplifiers.
    • OPTIMIZING CODED 16-APSK FOR AERONAUTICAL MOBILE TELEMETRY

      Rice, Michael; Josephson, Chad; Perrins, Erik; BYU, Dept Elec & Comp Eng; Univ Kansas, Dept Elec Eng & Comp Sci (International Foundation for Telemetering, 2017-10)
      This paper investigates the application of 16-APSK modulation to aeronautical mobile telemetry. The peak-to-average power ratio vs. code rate tradeoff is mapped to an optimization problem involving spectral efficiency and the constellation parameters. The optimization results produce a theoretically optimum solution that is 3.95 times more spectrally efficient as uncoded SOQPSK-TG. When implementation losses and the available IRIG 106 LDPC code rates are factored in, the advantage drops to 3.20 times the spectral efficiency of SOQPSK-TG.
    • A SUMMARY OF DATA-AIDED EQUALIZER EXPERIMENTS AT EDWARDS AFB

      Rice, Michael; Hogstrom, Christopher; Nash, Chris; Ravert, Jeff; Saquib, Mohammad; Afran, Md. Shah; Cole-Rhodes, Arlene; Moazzami, Farzad; Perrins, Erik; Temple, Kip; et al. (International Foundation for Telemetering, 2017-10)
      This paper summarizes the analysis of bit error rate data captured during flight tests designed to compare data-aided equalizers with SOQPSK-TG to unequalized and currently available blind, adaptive equalizers with SOQPSK-TG. The number of bit errors,on a second-by-second basis, are analyzed. The results are different for each test point. Given the uncertain behavior of the preamble detector for the data-aided equalizer and the differing channel conditions between the data-aided equalizer channel and the conventional serial streaming telemetry channel, we are unable to draw any firm comparative conclusions.