Single-Carrier Cyclic-Extension block DFE in time varying channels

The increasing data rates in wireless mobile systems involve transmitting in wideband channels giving rise to multi-path propagation. The classical way to attenuate intersymbol interference due to multipath channels is to use time domain equalizers, which are complex if the channel has many taps. OFDM signals allow an easy equalization of multipath channels, although the resulting high peak to average power ratio (PAPR) associated to this modulation produces a high power consumption, which may be unacceptable for mobile devices. However, it is possible to conceive a hybrid system where downlink uses OFDM and uplink uses single-carrier cyclic-extension (SC-CE) in a form that the implementation issues can be relaxed in the mobile. In this work we study a frequency domain decision feedback equalizer (DFE) for the uplink of such a hybrid system. Simulations show that RLS algorithm has faster convergence rate than LMS. Furthermore, RSL algorithm is able to track time varying channel better than the LMS solution.