Convolutional code and signal waveform design for band-limited satellite channels

A bandwidth- and power-efficient modulation system that combines convolutional encoding and phase modulation is presented. Signal waveforms are chosen to achieve controlled intersymbol interference and to satisfy a given out-of-band emission constraint. Convolutional codes are chosen to maximize the minimum free Euclidean distance between the modulator output signals including the effects of filtering. Maximum likelihood demodulators are used to recover the messages. System performance is evaluated in terms of RF spectral properties and the bit error rate versus energy per information bit over noise density. The results are compared with those of the conventional QPSK system for the additive white Gaussian noise and Intelsat V TDMA channels.