Decode-and-forward relaying technique in UMTS networks

As fading due to multipath propagation is an important issue in wireless systems, diversity techniques are employed in order to reduce the multipath fading effect. Cooperative communication represents a new class of diversity schemes in which multiple nodes equipped with a single antenna cooperate to generate a virtual multiple-antenna transmission system and thus offer the benefits of spatial diversity. This paper investigates the performance of the well known decode-and-forward cooperative technique on the flat fading indoor channel and also on the pedestrian and vehicular frequency-selective fading channels with decision feedback equalisation, which model the physical layer of UMTS networks in different environments. The performance is evaluated in terms of bit error rate as a function of signal-to-noise ratio with simulation results showing that decode-and-forward relaying provides a remarkable performance improvement over direct transmission.