On the MMSE iterative equalization for TDMA packet systems [articol]

Abstract

Original turbo equalization using a trellis-based channel equalizer and channel decoder improves significantly the bit error rate performance. However, a large alphabet modulation employed in the systems with multipath channels requires an excessive high number of states in such equalizer, so the optimal maximum a posteriori probability (MAP) becomes prohibitively complex. Therefore, sub-optimum equalizers with a priori information from the channel decoder have to be considered in order to enhance its performance. In this paper we investigate the performances of minimum mean square error (MMSE) filter based iterative equalization for the Enhanced General Packet Radio Service (EGPRS) radio link. The simulation results demonstrate that MMSE turbo equalization constitutes an attractive candidate for single-carrier wireless transmissions with multilevel modulation, in long delay-spread environments.