Cooperative Orthogonal MIMO-Relaying for UWB Ad-Hoc Networks

This conference paper proposes and investigates the cooperative orthogonal multiple input multiple output (MIMO) relaying strategies that can be adopted to forward data within UWB ad-hoc networks. We study two related issues: We derive the formula for the cooperative orthogonal MIMO-relaying with all channels´ information under the amplify-and-forward data relaying policy, and present the conditions for different data forwarding scenarios to realize orthogonal MIMO-relaying or that via own component suppression. Further, we propose three approaches to calculate the amplifying parameters at relays. Simulation studies show that for given data forwarding scenario if the relay number satisfies the least requested number, all three approaches can realize orthogonal MIMO-relaying or that via own component suppression. With the least requested number of relays, all three approaches exhibit the same diversity order (one), and that the seemingly best approach with channel-matched weights is worse than the other two approaches, i.e. the one with channel phase-matched weights and the one with all-equal weights.