Digital encoding of phase shift keying voiceband data signals

Computer simulation was used to evaluate the performance of eleven coder/decoders (codecs) with phase shift keying (PSK) voiceband data signals. The codecs were PCM, differential PCM and delta modulation systems designed for speech and operating at bit rates from 16 to 64 kb/s. The voiceband data signals processed by these codecs were demodulated to determine the phase error caused by the codec. Three performance metrics were used to evaluate the performance of these codecs-signal to quantizing noise ratio, variance of the phase error and maximum value of the phase error.