Three scheduling schemes for amplify-and-forward relay environments

This letter deals with the scheduling in basic amplify-and-forward relay environments, which are characterized by one source and two destinations. The scheduling strategy is required in order to decide which node will be used as a relay. The proposed schemes are the classical Round Robin, and a channel-based scheduling policy which requires a partial feedback from the channel. This scheme is implemented in a centralized and a distributed version. Simulations and analytical results show that the distributed algorithm outperforms the Round Robin and is 3 dB worse than the centralized algorithm, due to possible collisions or outage scheduling. This algorithm provides the best trade-off between performance and complexity and is attractive for practical implementations.