Applications of reduced state sequence estimation to terrestrial digital radio links

Applications of reduced state sequence estimation (RSSE) to the design of receivers for terrestrial digital radio links employing trellis coded modulation (TCM) are investigated and compared to standard techniques that separately perform the specific tasks of equalization and TCM decoding. Numerical results based on computer simulation are provided, showing that a significant performance improvement is attainable by a receiver based on RSSE for typical radio-link channels affected by intersymbol interference (ISI) and thermal noise. In addition, special attention is devoted to the receiver complexity, expressed in terms of number of equalizer taps and number of states of the assumed trellis diagram. Most of the potential gain is shown to be attainable by receivers of affordable complexity