Implementation of coded modems

Modem implementation techniques that have been proposed to achieve good error probability (P/sub e/) performance in various channel environments and to allow miniaturization of trellis-coded modems are presented. The application of trellis-coded modems, coding and mapping, a quadrature modulator subsystem, and quadrature demodulator subsystem, including carrier-phase offset, carrier slip, automatic frequency control (AFC), and automatic gain control (AGC), is discussed. Also addressed are Viterbi decoder design techniques and the implementation by digital signal processors and LSI circuits, as well as demodulators for Rician fading channels.<>