Robust transmit strategies for multiantenna bidirectional broadcast channels
Rafael F. Wyrembelski, Tobias J. Oechtering, Holger Boche, Mikael Skoglund · 2012
In this work the multiantenna bidirectional broadcast channel under channel uncertainty is studied. This problem is motivated by the broadcast phase of the decode-and-forward bidirectional relaying protocol, where a relay node establishes a bidirectional communication between two other nodes while having only imperfect channel state information available. Different uncertainty models are investigated, where the nominal channels experience either a multiplicative or additive perturbation based on a spectral norm constraint. For these uncertainty models the corresponding capacity regions of the multiantenna bidirectional broadcast channel are analyzed. Further, robust transmit strategies are characterized and worst-case perturbations are identified.