Browsing International Telemetering Conference Proceedings, Volume 45 (2009) by Authors
A System-Level Description of a SOQPSK-TG Demodulator for FEC ApplicationsPerrins, Erik; Rea, Gino; University of Kansas (International Foundation for Telemetering, 2009-10)In this paper we present a system-level description of a demodulator for shaped offset quadrature phase shift keying, telemetry group version (SOQPSK-TG) for use in forward error correction (FEC) applications. We describe the system in block-diagram form and provide implementation details for data sequence detection, symbol timing synchronization, carrier phase synchronization, and block recovery. This decision-directed demodulator is based on maximum likelihood principles, and is efficiently implemented by the soft output Viterbi algorithm (SOVA). We also provide results of the demodulator's performance in the additive white Gaussian noise channel, based on the observed bit error rate at different signal-to-noise ratio levels.