Análisis de prestaciones de algoritmos pseudo-mlse en sistemas TCM aplicados a comunicaciones móviles

Abstract

This article describes the problematic of using TCM (frellis Coded Modulations) in a mobile indoor environment characterized by a fast fading Rayleigh channel. This modulation technique involves the use of MLSE (Maximum Likelihood Sequence Estimation) algorithms (Viterbi algorithm), with the problem of exponential increasing of the number of surviving paths along with the interferent samples of the channel. To avoid this problem severa! NMLSE (Near MLSE) algorithms have been proposed . In this paper we consider one of these consisting in an adaptive threshold that limits severely the number of survivors. Different studies of the behavior of this algorithm, alone or assisted with Frequency Hopping and/or interleaving techniques, will be shown.