Coded-modulation enhancements to an HF single-tone modem

This paper present a modified MIL-STD-188-110A single-tone modem that achieves better performance than the standard waveform at higher data rates. The higher data rates are achieved by replacing the standard signalling waveform with carefully selected trellis-coded modulation schemes. Bit error rate (BER) performance curves show the superiority of the waveforms, especially when incorporated with an automatic repeat request (ARQ) scheme.