Digital processing of music for satellite communication

Subjective evaluations of processed music signals received over analog and digital circuits provided a test of different methods of encoding and modulating music for satellite communications systems. The digital processors included adaptive delta modulators, pulse code modulators and companded pulse code modulators. The analog signal simulated the type of signal and noise received from a conventional FM receiver. Results indicated that listeners perceived little difference between an FM signal with 50- or 60-dB signal-to-noise ratio and a 400 kb/s linear pulse code modulated signal.