Non-Coherent Receiver Design for MFSK Modulations in Deep Space Missions

Abstract

This work presents a non-coherent receiver architecture for coded MFSK transmissions in deep-space scenarios. First, we review the statistical characterization of the optimal (uncoded) detector output for both waveforms under consideration: conventional and special MFSK modulations. Based on the output statistics, we then derive the soft-demapper and provide approximated expressions for soft-inputs (log-likelihoods) to the channel decoder. The work has particularly considered performance/complexity trade-offs to enable real-time operation in scenarios characterized by very low SNR and channel dispersion caused by the Doppler dynamics and scintillation effects. End-to-end performance results including MFSK demodulation and LDPC decoding are provided for short telemetry frames.