This work aims at investigating the performance of a decoupled space-time processing structure based on a delayed decision-feedback sequence estimator (D-ST-DDFSE), in the context of the Enhanced Data rates for GSM Evolution (EDGE) system. The main idea in using decoupled space-time (D-ST) processing structures is to separate co-channel interference (CCI) reduction from intersymbol interference (ISI) suppression. Consequently, all degrees of freedom of a space-time (ST) front-end are dedicated to treat CCI, leaving ISI to be suppressed by a temporal equalizer. Due to the 8-PSK modulation and the large delay spread values compared to the symbol period, optimum detection becomes too complex in the EDGE system, which makes DDFSE a promising scheme for ISI suppression. The performance of D-ST-DDFSE is analyzed through link-level simulations under the context of COST 259 channel models for typical urban (TU) and bad urban (BU) propagation scenarios. Improved performance of this D-ST technique over a space-time linear equalizer is observed.