Distributed space-time codes for cooperative wireless networks in the presence of different propagation delays and path losses

The application of a distributed space-time coding scheme in a simulcast network is considered. A key challenge is addressed which is particularly crucial in the downlink: since the distances between the individual transmitting nodes and the receiving node are typically different, the transmitted signals are subject to different propagation delays and to different path losses. The influence of these effects on the system performance is investigated for the example of a specific space-time coding scheme, based on simulative and analytical results. Specifically, the issue of equalization/detection at the receiver is addressed, and a joint equalizer/detector algorithm of practicable complexity is proposed for large relative propagation delays.