AN ADAPTIVE MODEM, A PRAGMATIC DECODER AND DECODING METHOD EMPLOYED IN THE MODEM

摘要

Disclosed is a pragmatic decoder for receiving data encoded by an 8-PSK (phase shift keying) trellis encoder, and using a Viterbi decoder to decode the data, which comprises: an 8-PSK demodulator for demodulating signals transmitted by the trellis encoder; a quantizer for receiving signals from the 8-PSK demodulator, and using a constellation mapping configuration with reference to 0 degrees to detect n constellation position sections; and a soft decision unit for using a constellation position section detected by the quantizer to output a soft decision signal for converting it to I and Q signal arrangements needed for Viterbi decoder inputs.