Reduced state sequence estimation techniques for digital subscriber loop application

Reports a computer simulation study of two reduced state sequence estimators (RSSE) algorithms for equalization of severe intersymbol interference (ISI) on digital subscriber loops. The results show that the proposed algorithms can exceed the performance possible from the more conventional decision feedback equalization (DFE) receiver and thus allow longer reach. The noise considered in simulations, modelled by coloured noise, was near-end crosstalk, which is a dominant source of noise in DSL systems. The RSSE schemes´ advantage in reach was especially large for a cyclostationary crosstalk model. This model applies if crosstalk comes mainly from a few neighbouring twisted pairs or if all DSL signals are transmitted phase-aligned from the central office