ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / SOQPSK-TG is a highly bandwidth-efficient constant-envelope modulation so that it has been applied in airspace telemetry widely. We compare four types of coherent detectors for SOQPSK-TG, which are optimal detector, pulse truncation (PT) detector, standard OQPSK detector and modified OQPSK detector. The simulation and analysis results indicate that PT detector has the advantages of low complexity and good performance, so it has more practicality value.