A new cooperative transmission scheme using the space-time delay code

We propose a new resource efficient transmission scheme to achieve cooperative diversity of a distributed smart antenna system consisting of an information source, destination, and two alternating supportive relay stations. Each station is equipped with one antenna element. Furthermore we assume perfect synchronization and channel knowledge at the receivers. The proposed linear encoding functions with interference cancellation at one relay station result in an equivalent space-time delay coded system, but with additionally colored noise from the relay stations. Based on the maximum likelihood sequence estimator we derive criteria to evaluate the performance compared to the direct SISO transmission. Finally the numerical simulation results of an suboptimal sequence estimator show significant performance gains if the power gain from the hopping is gainful exploited. If not, the additional noise from the relay stations will degrade the performance at reasonable transmit powers