Adaptive decision feedback equalizers to combat time dispersion on the mobile radio channel

In mobile radio communication the time dispersion due to multipath propagation is a problem when the bit time used is on the same order as the delay spread. In that case, the intersymbol interference (ISI) can be quite severe. To combat ISI, the author studies the adaptive decision feedback equalizer (DFE), updated with different recursive algorithms. The equalizer is designed for staggered QAM (SQAM) modulation, which can be made with almost constant envelope and thus is well suited for mobile communications. Furthermore, GMSK (Gaussian minimum-shift keying) modulation can be approximated as SQAM. These modulation methods, as well as QAM, are simulated on different channels, with different adaptive algorithms