Optimization of distributed space-time filtering
Simon Yiu, Robert Schober, Lutz Lampe · 2006
Distributed space-time filtering (DSTF) has been re- cently proposed in (1) to increase the diversity in cooperative wire- less networks. In DSTF each node in the network is assigned a signature filter vector (SFV) and nodes cooperate without know- ing their partners. In this paper, we derive an approximation for the pairwise error probability of DSTF and use the result- ing expression for the optimization of SFVs. Two methods are provided for efficient filter calculation. Furthermore, unlike the original DSTF scheme in (1), we do not require the number of ac- tive nodes to be equal to the length of the SFVs, which is shown to result in additional performance gains. Simulation results show that the novel SFV designs outperform the previously proposed design even if non-ideal effects such as suboptimum equalization, imperfect channel estimation, and imperfect timing synchroniza- tion are taken into account.