• Preamble Design for Symbol Timing Estimation from SOQPSK-TG Waveforms

      Erkmen, Baris I.; Tkacenko, Andre; Okino, Clayton M.; California Institute of Technology (International Foundation for Telemetering, 2009-10)
      Data-aided symbol synchronization for bursty communications utilizes a predetermined modulation sequence, i.e., a preamble, preceding the payload. For effective symbol synchronization, this preamble must be designed in accordance with the modulation format. In this paper, we analyze preambles for shaped offset quadrature phase-shift keying (SOQPSK) waveforms. We compare the performance of several preambles by deriving the Cram´er-Rao bound (CRB), and identify a desirable one for the Telemetry Group variant of SOQPSK. We also demonstrate, via simulation, that the maximum likelihood estimator with this preamble approaches the CRB at moderate signal-to-noise ratio.