On the design and realization of adaptive equalization for mobile communication

In this paper the reduction of intersymbol interference (ISI) in mobile communication channels is addressed. A well known technique for ISI reduction is adaptive equalization in which the time-varying characteristics of the mobile channel are tracked by an adaptive algorithm. We compare different adaptive strategies and equalizer structures with respect to overall system performance in terms of computational complexity, numerical stability, finite wordlength effects, size and power consumption required for VLSI implementation. The adaptation strategies addressed are linear forward, decision feedback equalization. The selected algorithms are simulated in the Signal Processing Worksystem (SPW) tool complying to the Global System Mobile (GSM) standard and the Digital Enhanced Cordless Telecommunications (DECT) standard. The performance of the pertinent algorithm is expressed as the bit error rate (BER) versus the signal-to-noise ratio (SNR). Robustness and stability, the effects of finite wordlength and expected power consumption are presented as well.